This reverts commit 7debfc47.

...and a host object property on InteractiveScriptGlobals.

This is a first cut and my main goal at this point is forward
compatibility.  The existing unit tests all pass.

TODO: Make some improvements to the existing behavior.
TODO: Update the existing test baselines.
TODO: Introduce new tests.

This branch should be buddy testable - tweak the existing formatter by
subtyping (e.g.) `CSharpObjectFormatter` and assigning an instance of your
subtype to the global `ObjectFormatter` property.  It should be consumed
by subsequent submissions.

...and update namespaces contained therein accordingly.

...and update namespaces contained therein accordingly.

This has a number of small changes necessary for CoreFx support:

- Thread through the client directory to CommonCompiler.  This is
necessary for loading items like the SqmData.
- Move GetAssemblyVersion and GetAssemblyFileVersion into
CommonCompiler.  There is no need to specialize this for each compiler.
- Change the implementation of the above methods to not rely on
Assembly.Location which isn't present in CoreFx.

closes #1974

This changes the compiler APIs to no longer use
RuntimeVersion.GetRuntimeDirectory to find the path to mscorlib and
System.dll for the following reasons:

- This API is not available in CoreFx and hence blocks our transition.
- This behavior of implicitly referencing mscorlib doesn't have a
logical equivalent in coreclr where there may be no reachable mscorlib
on the machine (think Linux).

The compiler now takes the SDK search directory as a paramater.  The
consmer will be responsible for feeding down the correct value to the
compiler.

This is the first step in resolving issue #1939

closes #1943

The common parts of the compiler were attempting to deduce the directory
of the compiler exe by using various reflection / assembly APIs.  This
is a fragile method that is easy to break in unrelated code.
Additionally this API is not available on CoreFx.

The fix is to simply thread the compiler exe path through from the Main
methods on the EXE.

closes #1705

Made a number of small changes to enable building on CoreFx

- Remove uses of MemoryStream::GetBuffer.  This API isn't supported on
CoreFx. The TryGetBuffer is available but in these cases seemed better
to just call Stream::CopyTo
- Changed Type.Assembly to Type.GetTypeInfo().Assembly
- Moved scripting APIs out of CommonCompiler and into
ScriptCompilerUtil.  These methods relied on APIs that are not available
on CoreFx and have no equivalent.
- Minor API updates.

This moves the InMemoryAssemblyProvider out of CodeAnalysis.Desktop.
Because of its use in a high number of leaf project it is now included
as a linked file in those cases.

The loading of analyzer DLLS is now controlled by the compiler host.  It
is a behavior the host is forced to provide via the abstract member
CommonCompiler.AnalyzerLoadFunc.

When a compilation fails the compiler should not delete or edit the outputs of a previous successful.  They should remain around to satisfy scenarios like F5 on build failure.

Roslyn implemented this logic by doing the following:

- Creating a `Stream` for the assembly / PDB in a temp directory.
- Running the compilation.
- Moving the `Stream` to the desired output location on success.

This introduced a subtle bug into the compiler.  When the source + dest of `File.Move` are on the same volume the destination file will end up with the ACLs it got from being created in the source directory.  In this example it meant the assembly / PDB had the ACLs of the temp directory not the actual output one.

This can produce breaks in cases where the temp and output directory have different inheritable ACLS.  This case comes up for instance in ASP.Net.

To fix this we are going back to the native compiler behavior here.  The creation of the `Stream` objects will be delayed until we are ready to write to disk (happens after the compilation is verified to have no errors).

Because this portion of the compiler is on .NET 4.5.2 the Emit layer cannot open the files directly (no file system API to use).  Instead we pass down the `EmitStreamProvider` abstraction from the desktop layer and let that control the openning of the files.

This change also allows us to remove all of the temp directory logic from the compiler and build protocol.

Note: Whether or not to make this entry point a public API is being considered separately from this thread.  If we decide to make this public it will be done as a separate follow up change.

Bug-1116460 : Renaming the scripting assemblies and namespaces. Making corresponding changes in InstallDogfood and RoslynBuildAndTtest to account for new names (changeset 1408119)