Clearing notifications properly

(I may screw up this pull request, it's the first time I've tried this, sorry)

I recently pushed two commits to the CarbonDev fork of the Mms app. These commits fix notifications not clearing in certain situations. These commits have since been merged in Carbon and haven't broken anything, and I've heard that people have been experiencing the same issue in CM11, so I'm trying to create a pull request to merge those commits into CM.