Initial code commit

Initial commit of a WebSocket server implementation using the Chrome App
socket API. This is not yet a complete implementation of RFC 6455; some
parts are not implemented or the implementation is not complete:
* Binary frames are not supported.
* Payloads larger than 65535 bytes are not supported. The implementation
at least doesn't choke but instead sends a close with status 1009.
* Pong responses to server initated pings are accepted no matter what.
This is mainly due to the difficulties of using the Chrome alarms API
instead of a traditional setTimeout call.
* Not all nuances of the spec are implementated; e.g. verifying the mask is
set on close requests, etc.

External dependencies:
* CryptoJS for SHA1 and Base64 encoding of the Sec-WebSocket-Accept
response header during the handshake. This can be replaced by anything
that does valid SHA1 hashing and Base64 encoding.