Bug 1058459 - [SMS] Data shared from other applications are not shown as Drafts until the app is killed and open again.  r=schung

Using localStorage as inter app communication bus.
Most of the code in this file is related to my attempt to get rid of "dead" ports, so I chose "ack-rcv" strategy. If port doesn't answer during some period of time, I'm removing it from the broadcast list. Maybe there is better way, but I was able to find it yet :(