Update version 0.7.6 -> 0.7.7
Update version 0.7.6 -> 0.7.7

- Documentation
- Drop hixie-75 support
- Bug fixes

Review URL: https://codereview.appspot.com/6633052
googlearchive/pywebsocket,google/pywebsocket,GoogleChromeLabs/pywebsocket3,googlearchive/pywebsocket,GoogleChromeLabs/pywebsocket3,googlearchive/pywebsocket,google/pywebsocket,google/pywebsocket,GoogleChromeLabs/pywebsocket3