Fix failure in FileStream lightup on contracts

Fixes #249 : Fix IDE diagnostics test framework to use DiagnosticAnalyzerService to compute diagnostics rather than DiagnosticAnalyzerDriver.

This change serves multiple purposes:
1) Makes our test framework consistent with the IDE scenario in fetching diagnostics. We have missed out on multiple regressions where the core IDE DiagnosticAnalyzerDriver does the right thing and hence the tests pass, but the DiagnosticService in IDE does additional filtering and certain diagnostics are not reported in VS. This change should avoid such bugs.
2) Enable testing for diagnostics V2 engine work that JohnHamby is doing to merge IDE and compiler analyzer drivers. For this engine, there is no IDE driver and hence existing IDE diagnostics tests can't be run. This change should enable running IDE diagnostic tests on V2 engine.
3) Move a whole bunch of test only code in DiagnosticAnalyzerService_Test.cs into the test layer.

The initial attempt at a linux build script.  For now this is very
simple: just build csc.exe on Linux.

A simple typo is causing Type.GetType to fail when trying to load File.

Add a new switch '/errorlog:<file>' to VB and C# command line compilers to log all the compiler and analyzer diagnostics into a log file.
Add command line parsing tests and error log content validation tests.

Suppess Line Operation Within SingleLined Property AccessorList

Add a new switch '/errorlog:' to VB and C# command line compilers to log all the compiler diagnostics into a log file.
Add command line parsing tests and error log content validation tests.

Fixes #249: Fix IDE diagnostics test framework to use DiagnosticAnalyzerService to compute diagnostics rather than DiagnosticAnalyzerDriver.

This change serves multiple purposes:
1) Makes our test framework consistent with the IDE scenario in fetching diagnostics. We have missed out on multiple regressions where the core IDE DiagnosticAnalyzerDriver does the right thing and hence the tests pass, but the DiagnosticService in IDE does additional filtering and certain diagnostics are not reported in VS. This change should avoid such bugs.
2) Enable testing for diagnostics V2 engine work that JohnHamby is doing to merge IDE and compiler analyzer drivers. For this engine, there is no IDE driver and hence existing IDE diagnostics tests can't be run. This change should enable running IDE diagnostics on V2 engine.
3) Move a whole bunch of of test only code in DiagnosticAnalyzerService_Test.cs into the test layer.

update EnC unit tests to use localized resources

Fix #1298 Add suppress operation to span of the property including the
Property along with Accessorlist if it contains an initializer in
addition to the supress operation that goes over the whole of the
Property Declaration Statement

Start a global operation during project disconnect

Fixes #1294 

Handle null AccessorList in expression bodied properties

Mark SyntaxFacts.IsLambdaBody as obsolete

Re-enable EvaluateInitializerExpression test

Fixes #1300

Convert FakeSign to a NuGet reference

Fixed an errant bad line ending

Delay-load Roslyn services

Commit bcb2c8c7 added an `[Import]` of `IDiagnosticAnalyzerService` to
our Solution Explorer code. Unfortunately, this causes us to compose and
load effectively all of Roslyn whenever the Solution Explorer is opened,
even if no C# or VB code is loaded.

The fix is to delay pulling in the `IDiagnosticAnalyzerService` until we
actually need to make use of it, which is guaranteed to be after we have
loaded a C# or VB project (and thus we've already loaded Roslyn).

Fixes #1297 a crash in line separators.  I also took a look around for
other places where we access BasePropertyDeclarationSyntax and tried
to tighten them up too.

Qualify member accesses with type name in nameof

Fixes #1193

During expansion, directly accessed members need to be qualified with
"this." or "TypeName.". Prior to this change, we always qualified
instance members with "this." and static members with "TypeName.", but
this technique fails in nameof contexts where an instance member can be
referenced from a static method, resulting in an improper "this."
qualification. We can only legally use "this." when both the member
being accessed and the context from which we are accessing it are
non-static. However, this change updates the expanders to always use
"TypeName." qualification in nameof contexts regardless of the
staticness of either member because it is always legal and feels more
natural in nameof expressions (where no actual value is being accessed).

Handle unsupported diagnostics reported by analyzers.

Fixes #252 : If an analyzer reports a diagnostic with an unsupported diagnostic ID, i.e. no descriptor returned by SupportedDiagnostics has that ID, then throw an ArgumentException in ReportDiagnostic method. This exception would be turned into an analyzer diagnostic by the driver and reported back to the analyzer host.

Also fix a few tests that were reporting diagnostics with unsupported ID!

Fixes #252 : If an analyzer reports a diagnostic with an unsupported diagnostic ID, i.e. no descriptor returned by SupportedDiagnostics has that ID, then throw an ArgumentException in ReportDiagnostic method. This exception would be turned into an analyzer diagnostic by the driver and reported back to the analyzer host.
Also fix a few tests that were reporting diagnostics with unsupported ID!

Sort nodes by location before determining contiguous spans encompassed b...

CommonSyntaxNodeExtensions.GetContiguousSpans() was incorrectly assuming that the supplied nodes will be in the order in which they appear in source. This helper is used in the analyzer that produces diagnostics to grey out unused usings (i.e. to produce one diagnostic for a set of contiguous unused using directives).

Due to the above incorrect assumption, we would end up producing a single diagnostic spanning multiple unused usings sometimes and multiple diagnostics at other times. Often different invocations of the analyzer for the same source file would produce different set of unused usings diagnostics.

While this does not cause observable problems in regular usage - this is a problem for tests and led to flaky behavior where test would pass sometimes and fail at other times.

VB EnC: enable editing methods with lambdas and LINQ - merged

Use TryGetValue when looking up cached SyntaxContexts

Use Unicode escape sequences for control characters