* websocket.el: Fix process-coding-system for client connections.
  We previously set the coding-system to unix for encoding and
  decoding, then overwrote it with binary for encoding but not
  decoding.  I don't know why that happened, now we'll just set the
  coding system to binary for encoding and decoding, which fixes an
  issue with connections on Windows.
* websocket.el: Remove use of buffers in connections. This simplifies
  the code somewhat, and we avoid any possible buffer leaks.
* websocket.el: Throw clear error when connection cannot be made.