Basic parsing of # type: (...) -> t signatures
Fix to parse error handling + more tests
Get rid of spurious parse errors
Reject duplicate type annotations
Update old type syntax in error messages
Add semantic analyzer test case
Check number of args in comment signature
Fix methods with comment signatures
Add semantic analysis test case
Remove unused code
Fix nested functions with comment annotations
Remove unneeded attribute from Parser
Add comment after line break to Break token

This is more logical and makes parsing # type annotations easier.
Allow function comment annotion on separate line
Add function comment annotation test case
Fix lexing comments/whitespace at end of file
Add # type comment test case
Remvoe extra arg kind of method with comment sig
Add # type signature test cases
Add signature comment test cases