This commit ensures that all tickers are stopped using defer ticker.Stop()
style. This will also fix one bug seen when a client starts to listen to
event notifications and that case will result a leak in tickers.
This is an effort to remove panic from the source.
Add a new call called CriticialIf, that calls LogIf and exits.
Replace panics with one of CriticalIf, FatalIf and a return of error.
Anis Elleuch