Fix #554: This fixes a crash that was caused by invoking a lightbulb
item that caused an Inline Rename session to launch when there's already
an inline rename session active. We now check for inline rename sessions
during lightbulb commit. If an inline rename session is active, we halt
the lightbulb commit and tell the user to complete their rename session.

This only prevents one (but probably the most frequent) manifestation of
a larger problem in which rename is trying to perform a series of
changes to the workspace that can be interrupted by some other feature
applying its changes to the workspace. This larger design problem is
tracked as #681.

cleaned code little bit based on PR feedback

this is first step to add that support. added solution crawler progress reporter and renamed some types to solution crawler. and some plumbing to pass around progress reporter

this is reported by editor team where we returning wrong tags for given span. it looks like we gave end position as length. this is a second time we did this mistake. probably because this code was based on the code that had this issue originally.

to prevent this from happening again, I added assert in base tagger class.

* this is hard to do in unit test since each unit test tests one specific tagger. if we forgot to add unit test to tests this specific issue for new tagger added, it will go unnoticed again.

The code base no longer uses StyleCop.  Removing lingering references to
it from the code base.

some code clean up based on PR feedback

Fixed a NullReferenceException introduced by the last commit (range
validation)

Use compact property getter syntax.
Added range checking to Signature's constructor.

little bit of refactoring over temporary stroage and text factory service to preserve encoding round trip

Handle additional documents in Preview engine.
This exposed a bunch of NREs in some editor features and text extension methods that didn't account for additional documents being opened in the preview workspace, these have been fixed with appropriate null checks.

Use a Func<IEnumerable<SymbolDisplayPart>> to represent the 'getter' for Documentation in SignatureHelp and thread that through the entire sig-help implementation.

Previously, the way one used a patter matcher was the following:

    var matcher = new PatternMatcher();
    Loop {
        var result = matcher.MatchPattern(candidate, pattern)
    }

Because of this, each time you called MatchPattern, the matcher would have to deconstruct the
pattern into its relevant components (for example, splitting it on dots and decomposing words out
of it).  Now, this decomposition was cached.  However, that still meant checking the cache on each
call to MatchPattern.  This check involved a lock as well as a dictionary lookup.

The new way to use a pattern matcher is:

    var matcher = new PatternMatcher(pattern);
    Loop {
        var result = matcher.MatchPattern(candidate)
    }

This approach means that we only need to decompose the pattern once.  From then on we can reuse
that decomposition for each value we test against.

Realize the Documentation for signature help items lazily.

moved v1 engine to its own namespace and updated sources accordingly.

also added BaseDiagnosticIncrementalAnalyzer which contains all methods that engine needs to implement to make all other services which consume IDiagnosticAnalyzerService to just work.

probably later we will change it but for now, this should let us test v2 engine isolated without too much changes in other part of code base

moved some more files around diagnostic incremental analyzer and added option to choose between two engines.

This will allow other features (like searching in Solution Explorer) to use the same
searching facilities that we've just added to NavigateTo.

NavigateTo doesn't support cancellation when computing the display properties so the cancellation token is getting removed rather than having to manually handling OperationCanceledException.

1. Reduce allocations when reading from FileStream.
2. Pre-compute checksum if possible.
3. Reduce allocations for lazily computed checksums.
4. Avoid LOH allocations for large source text.
5. Update EditorTextFactory to optimize for reads from temporary storage

Perf results for the Picasso rebuild scenario:
184 MB total allocations saved. Including: 78 MB of char[], 73 MB of Byte[], 9 MB of string. Also, 35 MB of LOH allocations were eliminated.
 (changeset 1412085)

No, if you search for something like CS.SK we'll find Microsoft.CodeAnalysis.CSharp.SyntaxKind

We do this by breaking up the original pattern by dots (so, in this case, we'd have "CS" and "SK").  We then do our normal search, looking for symbols that match the last name piece (in this case "SK").  When we find one, we then walk up it's container seeing if each parent container name matches each respective preceding pattern component.  If all pattern parts match, then the symbol is a match and it is returned.
***NO_CI***
 (changeset 1411849)

     * Gray background
     * No border
     * No padding on top or right
     * Colored bar at bottom of dashboard

     This requires us to set UseLayoutRounding=True, since we're trying to draw straight lines (https://msdn.microsoft.com/en-us/library/system.windows.uielement.uselayoutrounding%28v=vs.95%29.aspx). (changeset 1411219)

DescriptionModifyingCompletionItem should use the default task scheduler when computing the snippet text. Use of "TaskScheduler.Current" will deadlock if the UI thread is blocking waiting for a description."TaskScheduler.Current" would deadlock if the UI thread was blocking waiting for a description.

Note that this was previously checked into Dev14CTP as changeset 1350549 but somehow didn't get included when that branch RIed to Roslyn\Main. (changeset 1410908)

1. Stop displaying superfluous 'No Preview' under the header section of the preview pane for fixes such as 'rename tracking' and 'generate type dialog' that don't provide any visual preview.

2. Make preview pane header font use the VS 'Environment' font settings so that user can change /scale the font.

3. We were not displaying the preview header in the case of hidden diagnostics (which don't show up in the error list) - start displaying the header for hidden diagnostics (except if the diagnostic is a 'trigger' diagnostic).

4. Disable tab stop / focus in the code diff view portion of the preview pane. When using keyboard, we were allowing user to stop in the diff view portion - this ended up causing confusion since we would display a blinking cursor in the code diff view portion giving users the impression that they could type something there.

5. Set Focusable=true on the preview pane control. Light bulb checks for this before shifting keyboard focus to the preview pane in the case where there are no 'flavored' actions under the preview pane (such as 'Preview Changes' and 'Fix All Occurrences'). (changeset 1410707)

VS telemetry now has data type specific APIs that can be used to reprot various data type to server. once used, data can be manipulated better by reporting side. (changeset 1410375)

This will ensure that case sensitive matches are placed above insensitive ones in the NavigateTo results list.
***NO_CI***
 (changeset 1409531)

now it should properly re-tag editor when there are severity changes due to rule set changes or other changes. (changeset 1409269)

This is because peek uses symbolkeys to resolve symbols between compilations which could potentially be from different frameworks but symbolkeys do not contain enough information to deal with typeforwarding situations. E.g: a portable project and a non-portable project may both resolve the same Int32 symbol to System.Runtime and mscorlib.

Other features such as Metadata as source, Find References already do this. This change updates Peek to do the same thing. (changeset 1407182)

This affects what happens to tags for previous text snapshot versions that are mapped forward (in the interim period before we get the new up to date tags).

Most features just have EdgeExclusive behavior.  However, some features, like TypeScript classification, want EdgeInclusive behavior so that if you type at the edge of an existing tag, the next text gets the old classification and does not flash.
***NO_CI***
 (changeset 1406469)

also, made ITextFactoryService internal (changeset 1406337)

Brace matching has code to check for matching spans left of the caret - to deal with cases like {$$()}. We need to protect against negative numbers when caret is at position 0. (changeset 1405386)