Fixing dependency-cycle error messages.
Fixed injection of corlib types.

Known types were being imported incorrectly (via
module.Import(typeof(T))), with the result of references to the
compile-time versions of System.dll and mscorlib.dll being added to any
Fody-processed assembly.  For some reason this worked on Android, but
Windows Phone blew up.

Now it's fixed.
NullReferenceException on Windows Phone.
Adding a means of excluding classes from Fody processing by means of
the config file.  Re-using an old trie implementation for excluded-class
lookups.
Enhancing cycle-detection tests, which unfortunately means the
post-weaving tests won't compile them.  Excluding them from the
postweaving build.
Fixing some bad values for Binding.RequiredBy in compiler and reflection.
Exposing ModuleDefinition.TypeSystem types in References.
Fixing some more RequiredBy cases.
Cleaning up attribute argument parsing and simplifying some generated IL.
Disabling IProvider<T> injection in the Reflection plugin on MonoTouch.j
Fixing a stray RequiredBy bug.
Fixing post-weaving test build.  NEED MOAR INTEGRATION TESTS.