Update to a new version of the Roslyn Diagnostics analyzer package.

This is part of the fix of issue#4774.

This change does two actions to our public API files:

- Resets them to the versions from 1.0.0 RTM
- Splits them into the shipped and unshipped files

We no longer use SCC bindings in our project yet the definitions remained around and caused a dialog prompt on solution open.  Removing these as they are no longer needed

This only takes effect if you're building in a versionless command
prompt.

Rather than failing the build, if Roslyn is installed globally just
don't try to deploy.

Fixes #4189 (https://github.com/dotnet/roslyn/issues/4189)

This fixes the Build/AssemblyVersion to be the same as RoslynSemanticVersion when OfficialBuild is true, but no BuildVersion was passed in.

This fixed DevDiv.1158790 — Spurious errors, warnings and messages in IDE from background analysis, which
basically results in a bunch of warnings in the IDE:

     The referenced component 'C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETPortable\v4.5\Profile\Profile7\mscorlib.dll' could not be found.

C#/VB project system do not support conditional references and treat them as always being present. This <Reference was being included for all projects regardless
of the condition, confusing Visual Basic project system. Moved it to _ExplictReference concept which already exists for adding mscorlib (see <_ExplicitReference> in Microsoft.CSharp.CurrentVersionCommon.targets)

Adds two new projects, CscCore and VbcCore, which target CoreCLR and
produce CoreCLR-compatible executables in the core-clr subdirectory of
the build output. At the moment they are not included in any solution
because a bug in the DNX build tools that causes VS 2015 to deadlock
whenever the project files are loaded.

The targets files were previously split into an open version in
Microsoft.CodeAnalysis.Toolset.Open and a closed version in build/. This
unifies the four targets into two new targets, VSL.Settings.targets and
VSL.Imports.targets, and moves all the targets from ..Toolset.Open into
the build/ folder.

Our build system currently generates our final output to the Binaries directory but
puts the intermediate output into the source tree in obj directories.  This change unifies
the behavior by putting both intermediate and final output into Binaries.

Update versions of Microsoft.DiaSymReader and Microsoft.NetFX20 packages to release 1.0.5 and1.0.3, respectively

This reverts commit 7c525e81.

Update to version 1.0.0-rc3-20150510-01.

Builds in Jenkins will now self-host the compiler bits that result from
the changes being committed in the PR.  Hence if there is a bug
introduced by the change that prevents us from compiling Roslyn we will
find it out before checkin vs. the next toolset update.

This change causes the Jenkins build to roughly do the following:

1. Build the C#, VB and compiler server binaries and move them to
Binaries\Bootstrap.
2. Clean the enlistment which deletes the intermediate directories and
kill the compiler server.
3. Run our standard BuildAndTest.proj using the
/p:BootstrapBuildPath=Binaries\Bootstrap parameter to self-host the just
built compilers.

Also disable a unit test that fails with new toolset.

new version: 1.0.0-rc2-20150413-02

The previous name was easily confused with a boolean value.  Changed to
have the Path suffix to make the intent of the value clearer.