Handle TaskCancelledException in AnalyzerManager.GetAnalyzerActionsAsync

add support for error list IsStable - progress indicator

Use ReportFatalError in TaskFactory helpers

Handle failing conversion in synthesized code

cleaned code little bit based on PR feedback

AnalyzerManager maintains a cache of per-analyzer tasks to compute sessions and compilation analyis scopes. If multiple clients simultaneously ask for the analyzer actions for a given analyzer, then all of them receive the same task. If the thread that created this task is now cancelled, all other clients get a TaskCancelledException with a different cancellation token then theirs and the exception goes unhandled, bringing down VS.

Fix is to catch this task cancelled exception in AnalyzerManager, remove the entry for the the cancelled task in the scope map and then re-attempt computing scope, if our cancellelation has not fired.

Add options to FakeSign.exe
-u (unsign) reverses the default behavior by clearing the strong name signed bit.
-f (force) forces an update even if it would change nothing.

Don't allow -f to be used on assemblies that aren't managed.

Support setting the active rule set from Solution Explorer

Add the -f (force) option to force an update even if the file would
otherwise not be modified.

Add usage information for the "-u" option.

Use ternaries inside interpolated strings for error messages.

Add documentation clarifying C# compiler behavior for static types

Automated checkin: update Concord binaries from \\cpvsbuild\drops\dev14\VSPro_1\raw\22617.00 to version 22618.00.

Move enforcement of "no static type as type argument" to constraint validation

related to #324

Start Documentation for Compiler Specification

first working version. need some more tweaks.

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

add property bag to diagnostic and remember origin of the diagnostic

Fix CompileAndVerifyOnWin8Only test utility

Implement VB Code Model's AddAttribute method for several declaration kinds

Preprocessor symbols in VB need to be combined with a comma, not a
semicolon.

The primary use of DefineConstants should be to append constant values,
not replace them.  Any time a replacement operation is used it prevents
us from establishing defines in our targets and pushing them down to all
affected projects.

Improve SyntaxDiffer diffing rules

Include DefaultContentType in InteractiveCommand metadata

Partial fix for #409: Update StartsWith invocations to use appropriate StringComparison