committing fix for https://wso2.org/jira/browse/CEP-900
Merge pull request #21 from sacjaya/master

Merging fix from Sachini for https://wso2.org/jira/browse/CEP-900
Committing the unsubscription fixes for mqtt
Fixing mqtt reconnection issue
Merge branch 'master' of https://github.com/wso2-dev/carbon-event-processing