add pypy detection, only build ext in CPython.
fix pypy3 compatibility, enable pypy3.
Two new features:
 - Add support for includes. load() now takes an optional include_dirs argument that specifies relative paths.
 - Add support for service "extends".
Fix lint errors.
PY3 compat.
Slightly controversial: include the enum type in I32 definitions coming from enums.

This makes it a lot easier to build reflection-like tools, e.g. converting JSON to Thrift that might use strings for enums.
Still bad at lint.
added close() to servers
Merge pull request #37 from mikekap/develop

Add support for includes & service extends
Fix set constants.
Merge pull request #39 from mikekap/develop

Fix set constants.
add trans_factory args to make_server
update examples to latest recommended style
update docs and readme.

1. update cython usage examples
2. update features
3. remove TODOs since they were mostly done
Implement non-strict mode for the binary protocol.
Merge pull request #40 from mikekap/develop

Implement non-strict mode for the binary protocols
Fix is_open on framed transport.
Merge pull request #41 from mikekap/develop

Fix is_open on framed transport.
Merge pull request #38 from ritksm/develop

added close() to servers
unify args name in buffered tranport