Added support for precompiled binaries and refactored some stuff
- project.json can say (per target framework), what the behavior should be.
- Made IProjectExportProvider return the specific IMetadataProjectReference instead of the closure
- Added CompiledProjectMetadataReference for already compiled projects (or to consume output from
 other projects)
Updated to handle roslyn changes
Revert "Updated to handle roslyn changes"

This reverts commit 46bebbccd3244f68931f84a1f33ae3231442c39e.
Use Console.Error for printing out errors from BuildManager
Fix KRE lookup path in .cmd files generated by "kpm pack"
Refactoring GetLibraryExport
- Make each call to GetLibraryExport only resolve direct exports
- Walk the resolved dependency tree using the ILibraryManager
 to resolve transitive metadata references.
- Remove UnresolvedMetadataReference as it's no longer needed
More clean up
- Clean up logic in NuGetDependencyResolver to use the target framework
 passed into GetLibraryExport
- Resolve references inline
Added GetAllExports to ILibraryManager
- Reused ProjectExportProviderHelper for both ILibraryManager and
  ProjectLibraryExportProvider
Fixed build and design time host
- Changed ProjectBuilder and ProjectMetadataProvider to use
  ILibraryManager instead of ILibraryExport directly.
De-dupe source references
Small fixes and tweaks due to recursive roll up
- Use ILibraryManager for ProjectAssemblyLoader
- Change DFS to a BFS so we can look at dependencies in level order
- Only export source files from the top level
Initial changes to make kpm restore work on core clr
- Still doesn't support reading or writing private sources
- Still doesn't support proxies
Make "kpm restore" runnable on CoreCLR

- Copy essential dlls into KRE package manager dependency folder
- Resolve exception caused by multiple async readers/writers working on one
  DefalteStream
- Add support for basic authenticated proxy
Fixed the cache key for the the ProjectLibraryExportProvider
- Use the name, target framework and configuration
Adding scripts section to project.json

Launched by kpm commands via shell command processor
PR #493 feedback
String.Join now has an overload taking IEnumerable<string>
Revert "Revert "Updated to handle roslyn changes""

This reverts commit 069dfb964a86ab505dd6df5e5495434072346b6c.
Make "--verbose" option work for "kpm restore"
Updated configurations node in project.json
- Configurations no longer support target frameworks
- Changed casing of debug/release to Debug and Release by default