Merge in temporary Messaging Dev Branch

This is the list of things we determined had to be fixed before we could merge into master: https://wiki.mozilla.org/Gaia/SMS 

At this point the dev-branch now has all of these commits and we can move forward being based in master.

I acidentially pushed the rebase onto master before the branch, so this PR lost the commits - they are all the ones on top here: https://github.com/bocoup/gaia/commits/messaging-rebase (back to the one from daleharvey)