Bug 941176 - [Rocketbar] Add title to statusbar r=daleharvey

A new title resides in the statusbar. When rocketbar is enabled, notification icons are shifted to the right. The title attemtps to maintain proper state by listening to mozbrowser events.
Merge pull request #14902 from KevinGrandon/bug_941176_rocketbar_view_title

Bug 941176 - [Rocketbar] Add title to statusbar r=daleharvey