New error message for java interop
Improved line error reporting
Fixed test to align with new assignment error message. Also removed invalid subtype assertion.
Made imports typecheck & evaluate immedately
Java interop field support
Made TypeDeclarations typecheck their attributes
Scoping fixes
Added another lookup try for type internal values
Made the type conversion in classes a lot nicer
Fixed a bunch of issues working towards in-language parsers
Made Objs use a ref for their internal env.
Replaced old interop test with a new type extension based one.