Incorporate feedback from hellais, and minor bug fixes

Changed based on feedback from hellias:
 * handleCmdConnectFailure now traps errors
 * sendReply no longer deals with parsing out the outgoing local address
 * logging uses the obfsproxy logger again
 * Fixed a bug where send_reply was used instead of sendReply
 * The obfsproxy specific SOCKSv5 classes were renamed to OBFSSOCKSv5Outgoing
   and OBFSSOCKSv5Protocol

Bugs I found:
 * SOCKSv5Protocol.dataReceived() should actually work now (never called by
   obfsproxy since it's overridden)
 * _ByteBuffer.get_uint32() was always doing byte order conversion (method never
   used)