Manage the lifetime of DkmClrValue objects

Move VB end construct code fix away from CodeGenerator

We need to attach the same information to DkmEvaluationResults and
DkmEvaluationResultEnumContexts, but they have different lifetimes.  Enum
contexts, which are, in some sense, the children of evaluation results are
closed first.  As such we don't want to clean up our attached information
until the evaluation result is closed.  When we are informed that this has
happened (by a call to EvalResultDataItem.OnClose), we call Close on the
associated DkmClrValue.

We hope that actively managing the lifetime of DkmClrValue instances will
improve perf by reducing the amount of work that the debugger has to do on
each evaluation (which is proportional to the number of live
DkmClrValues).

Unfortunately, this will not improve perf in the large-array case because
DkmEvaluationResults are not closed as they are scrolled out of view.

Associated with DevDiv #1094428 (not yet on GitHub).

while creating pull request, I left out this change

fix vsct file to not have dupliate button definitions

Add MetadataVisualizer project to Roslyn solutions

Construct EnumContextDataItems on demand.  Also, don't access their properties before checking for null.

disable some tests due to interface tests.

these tests will be re-enabled once we patch build machine with new interfaces.

Conflicts:
	src/Roslyn.sln

Replace nonbreaking space (0xA0) with a regular space.

We need to attach the same information to DkmEvaluationResults and
DkmEvaluationResultEnumContexts, but they have different lifetimes.  Enum
contexts, which are, in some sense, the children of evaluation results are
closed first.  As such we don't want to clean up our attached information
until the evaluation result is closed.  When we are informed that this has
happened (by a call to EvalResultDataItem.OnClose), we call Close on the
associated DkmClrValue.

We hope that actively managing the lifetime of DkmClrValue instances will
improve perf by reducing the amount of work that the debugger has to do on
each evaluation (which is proportional to the number of live
DkmClrValues).

Unfortunately, this will not improve perf in the large-array case because
DkmEvaluationResults are not closed as they are scrolled out of view.

Associated with DevDiv #1094428 (not yet on GitHub).

It is likely the character was inserted by accident. There is no reason
to use it in the code. It is a valid Unicode whitespace, but not a valid
ASCII. Since the containing file has no encoding bytemarks, the behavior
of this char is dependent on default encoding. Indeed, the file compiles
on Windows and fails on Linux.
As far as I could find, this is the only case where this character is
used in actual code (not in tests) in Roslyn codebase.

Remove cancellation token from NavigateTo

Delete our copy of IsBuiltInRuleSet

Fix #308 and #306 - issues with dynamic expressions in string interpolation

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

Ensure that FileKey's timestamp is Utc by adding a Debug.Assert
Use LastWriteTimeUtc in MetadataCache.

This change deletes code we use to determine if a rule set file is one
that shipped with VS, and thus cannot be modified or deleted. It was
largely copied from code in
Microsoft.VisualStudio.CodeAnalysis.Sdk.UI.dll, and we should just use
the original instead.

Fix #323 bug in SemanticModel.GetAwaitExpressionInfo when await expression used as an expression statement.

Add the CodeAnalysis analyzers projects back to the Roslyn solution.

Fix #323 bug in SemanticModel.GetAwaitExpressionInfo when await expression used as an expression statement.

It looks like this got lost when the new open Roslyn.sln was created.

Corrected documentation on FullSpan and Span

Small fixes for running suites

The BuildAndTest.proj was failing because a number of our suites aren't
correct when run in parallel.  Disabling them for now and letting #321
track reenabling them.