Implement SMS mark for unread (Cyan-348)

Change-Id: I999e4159603d13062b535b2445cbc7efd3cf9b7b
Mms: Move Mark as unread strings to the correct places

* Strings go to cm_strings
* Plurals go to cm_plurals
* Fixed plurals for CM standards

Change-Id: I7227c27039188202b376ecf50d79c9918c3b456a
QuickMessagePopup: pager fix on multiple messages.

Fixed the pager to
* keep the already typed replies for each message, and
* retain the typing focus on the current message reply's EditText.

Change-Id: I48bc7e5c597dd31ae13a6ce81f33f870f9ec2be8
mms: Add CHANGE_PHONE_BLACKLIST permission

Fixes permission denial and subsequent FC when adding a contact to
blacklist from an SMS thread.

Change-Id: I3b33602684077d11f8d6473c538dc919c771127b
Stop previous TaskStack worker

Each time we delete all threads, a new TaskStack thread is started.
We need stop the previous one to avoid over memory consumption.

Change-Id: Ibee8dd7b8e757df0686c7989dc7d9878f9ef5102
Signed-off-by: Emmanuel Berthier <emmanuel.berthier@intel.com>