Import everything in websocketproxy and websocket

Old users of the websockify library used websockify.WebSocketProxy
The refactor into a module unneccessarily broke this import. The
current imports in __init__.py don't actually do anything so this
patch changes the import to import everything so that the old import
still works. This appears to be the original intention of the existing
import statements.

websockify/__init__.py

@@ -1 +1,2 @@
-import websocket, websocketproxy
+from websocket import *
+from websocketproxy import *