Add pytd for 'strop' module
Make pytd parser indent-aware
Add pytd for StringIO, warnings, codecs
Move node tests from parse_test.py to node_test.py.
Improve instantiation of pytd templates.
fix utils.GetBuiltins()
Manual pytd fixes
add missing quotes
Add Type marker class as a mix-in for all pytypedecl AST nodes that represent types.
Remove tee class from itertools.pytd as it conflicts with the function tee.

The class tee is an artifact of the python implementation and never actually appears in any other pytd type.
Make UnionType compare ignore ordering.

Fix float PyTD.
Add MaybeFillInClasses function to pytd.parse.visitors.
Fix a couple of small bugs in pytypedecl.
Fix failures caused by the change from list to tuple
Refactoring, add test case for JoinUnions.
Add support for type parameters on tuples, lists, dicts, and sets.
Move type inference tests into pytypedecl.

Also add some larger tests: pytree and StringIO. Both modified somewhat.
Grammar refactoring, rename PyParser to TypeDeclParser, remove provenance.
Make the pytree example code stand-alone and add tests to it.

Also, fix a bug in inference_tests with incorrect call to infer instead of
Infer.
remove unused tokens
Allow multiple levels of indent/dedent in pytd.