Reacting to Roslyn changes
Initial changes to rework the design time host
- Account for multiple target frameworks
Fixed framework name members
Refactoring message types
- Separated References and Dependencies messages
- Changed ProjectName to Name
- Changed ConfigurationData to a list of strings
Support the runtime retrieving compilations per target framework
- Added SendCompiledAssemblies and SendDiagnostics  for clarity
Added target to project references in design time host
- Round trip LibraryDescription description and added FrameworkName to
LibraryDescription.
- Set the target framework when resolving the project references and
always fallback to the requested framework
- Represent project references by a ProjectReference type
in DesignTimeHost instead of a string.
Change CompiledMessage to OutputsMessage
Skip main project when returning project refs
Allow loading native in the same folder as IL if the native image was not found in the arch folder