fix GC issue when run during CPG#send

How CPG#send worked at all is a damn good question. It should have failed 100% of the time...
Version: 0.2.0.0

* fix GC issue when run during CPG#send
  Patrick Hemmer (2014-03-15 15:04:19 -0400) - @ea140a5

* reorder arguments for CPG on_message callback
  Patrick Hemmer (2014-03-10 12:02:54 -0400) - @27c3add