Bug 951773 - Change mozdevice.removeFile and .removeDir to use _checkCmd
Bump mozdevice to 0.31
Bug 952420 - [mozprofile] Enable extensions in Metro. r=hskupin
Bug 952428 - Bump mozprofile to 0.19
Bug 924931 - Add tests for checking for java exceptions in mozcrash;r=wlach
Bug 852235 - Remove mozb2g;r=ahal

(see bug for rationale)