Move to F.C.S 0.0.10

This updates to use FSharp.Compiler.Services 0.0.10, which 
- gives better error messages on missing assemblies
- if asemblies are missing, then a dangling type reference returns false for "IsClass" etc., which makes client code more robust (and matches behaviour of the old PowerPack metadata API), rather than raising exceptions
- fixes a problem with FSharp.Core references in scripts which was causing a unit test to fail