Start using MethodLookup in MirrorTypeSystem.
Support infering method return type after visiting the declaration.
Support error types during method lookup.
Support infering argument types after the method def.
Delete obsolete code
Fix closures in a constructor.
Support deferred inference of superclass.
Add more of the basic types.
Implement packages
Implement imports
Implement widen, assignableFrom, super in constructor
Set main class name from filename.
Array support
Create DerivedFuture, and use it where appropriate.
Support arrays in the mirror loaders.
Implement math operators.
Implement real local scoping.
Add field accesses to method lookup.
Make scopes inherit package and imports.
Add no-arg constructor for tests.