CyTube has been crashing recently due to things attempting to release
the reference after the channel was already closed (apparently the
uncaughtException handler isn't called for this?). This newer
implementation keeps track of what is ref'ing and unref'ing it, so it
can log an error if it detects a discrepancy.
Also changed the server to not delete the refCounter field from the
channel when it's unloaded, so that should reduce the number of errors
stemming from it being null/undefined.
