Adds receivedmessages and uses polling to fetch messages from connection
small refactorings to connection
moves errors into own file
refactor connection to use channels rather than polling
Add flush message method to ws connection
Update readme to reflect ReceiveMessage returning error
Merge branch 'master' of git://github.com/wjdix/testflight into wjdix.

Closes #2.
Rename WriteMessage to SendMessage. Formatting changes.