Remove any unprocessed projects from remote

#794
The aspect name shouldn't flow down package dependencies

That was a mistaken assumption
This helps mvc preprocess scenarios
Made the PDB errors go away

#791
Initial plumbing of IAssemblyLoadContext and family
- Removed IAssemblyLoaderEngine and replace it with IAssemblyLoadContext
- Added Microsoft.Framework.Runtime.Loader which has implementations of
IAssemblyLoadContext and IAssemblyLoadContextAccessor for net45 and aspnetcore50
- Use current LoadContext to LoadFile and LoadStream in different loaders
Added IAssemblyLoadContextFactory abstraction
- This interface creates a IAssemblyLoadContext with relevant loaders
- Updated the NuGetAssemblyLoader and ProjectAssemblyLoader to allow passing
in an IAssemblyLoadContext.
- Updated the RoslynCompiler to create a child context when loading the
preprocess assembly.
- Made IAssemblyLoadContext disposable
- Fixed issues with LoadContext and infinite recursion
- Made IAssemblyLoadContext have Load(name)
- Handle ANI extraction on CoreCLR
Changed aspnetcore framework compatibility
- Updated JSON.NET to 6.0.6
- Removed win8 aliasing and added an temporary ugly heuristic for aspnetcore50
compat
- Added unit tests

#596
Use XDocument to do XML operations when generating web.config
Remove k.ini file generation during "kpm pack"
Add functional tests for web.config generation during "kpm pack"