Hextile working. Improve latency by coallescing sends.

- Hextile has an undocumented weirdness where RAW frames are often
  followed by a 0 byte that should be ignored.

- Coallesce client messages that are one after another. Without
  this the server seems to often ignore frames that are send right
  after another frame has been sent. This fixes a reconnect issue
  where setEncodings seems to be ignored. Also results in a huge
  performance increase after key strokes (by adding a update request
  to the key event message) because the server always sends an update
  instead of sometimes waiting for the next poll to be sent.