Remove unused dependency
Fix contract violations between parser and ast
Add untyped ast structs
Allow identifiers to be methods with no arguments, add more builtins
Add syntax->datum to unwrap syntax structure
Start typechecking method declarations and add self identifier to environment
Fix test
Fix find-method-in for self types
Typechecking for methods and objects should work now, with self being an identifier rather than a type
Add errors for undefined types in methods
Fix typechecking return statements and add method return types to the type env, fix subtyping for methods particularly
Redefine variables
Merge branch 'working'

Conflicts:
	grace/lang/typecheckR.rkt