#226: Added cancel option to ProgressDialogFragments. Create Key is now cancelable.
#226: Activity no longer closes if progress is canceled for key creation in EditKeyActivity
#226: Async key gen task is stopped if progress is canceled
#226: Small fix to prevent message from being sent if IntentService is canceled
Merge pull request #315 from jessicayuen/master

#226: Added cancel option to ProgressDialogFragments. Create Key is now cancelable.