Final set of spelling corrections in strings and comments.

Change AppConfigBasicFail to use a drive that is connected

made WorkCoordinator test to use its own MEF containers that are not shared with others

Update toolset compiler to 1.1.0-rc1-20151014-05

Do async locking correctly

AppConfigBasicFail fails at home because I have an "I" drive
that is plugged in. Change it to use an existent drive, so the
drive is connected, but the path just can't be found.

Changed "tests" -> "test assemblies" to better reflect what the test runner is doing

Fix for #5760

Zip

Fixes #5978.

This changes the Windows builds to restore in the same manner as Linux.  Helps ensure we keep the lab consistent between the runs.

The other positive upside of this change is shaves ~10 minutes of individual runs.  Roslyn.sln is a *huge* solution, has a rather large MSBuild include pattern and as a result puts a lot of pressure on restore.  As such the set of restores we do typically takes ~10 minutes.

Long term we'll be working with NuGet to get this time down a bit.  At the moment though we're a bit of an odd solution here with our size and time requirements.

Introduce xunit based performance testing

Re-unskip code model tests

Fix issue with code model eventing and VB type characters on parameter names

Fix a testing issue

Switch our CoreCLR projects to be ".NETPortable,v5.0"

Changed some tests from blocking waits to be properly async.

Ensure that flow analysis calls VisitRvalue instead of Visit for expressions in order to enforce proper state transition.

provide HelpKeyword information for offline help

Fix PublicAPI analyzer in our source tree

made CreateExportProviderWithCSharpAndVisualBasic to truely create new ExportProvider rather than underlying data might have been shared between multiple export providers.

Remove some debug-only code...

And update project.lock.json

This closes #6028, and #6001

that intentionally slowed down the code to help detect race conditions
Fixes #4337

Ensure that flow analysis calls VisitRvalue instead of Visit for expressions in order to enforce proper state transition.

Fixes #5992.

If logical expression is not visited with VisitRvalue method, current state remains splitted, which causes a NullReferenceException when the next expression is visited.