Add hasFired alias for Callback.fired.
Add deprecation comment about callback.fired.
Merge branch 'develop' of github.com:gameclosure/js.io

* 'develop' of github.com:gameclosure/js.io:
  errorReceived may not be defined
  remove supr call in error class
  Added some doc comments to files. Cleaned up math.round, which is a strange function.
  use ENV.pathSep to support windows; fix bug in cls preprocessor for invalid js character `:`
  new version released
  add delimiter back (unnecessary after base64 fix), removed socket.close (deprecated API)
  add a trailing semicolon in case it was stripped somewhere along the line
  allow preprocessors to import other files; add stack trace to import errors; add jsio.eval for evaluating arbitrary strings
  allow more special characters " and :
  backslash-r backslash-n wasn't working...