bug 952305

* use default gecko error message for all errors for which we do not have special handling.
** currently this means for all errors other than netOffline and dnsNotFound.

r=mhenretty
Bug 909877 - Enable APZ for all of gaia. rs=milan
Merge pull request #15089 from nullaus/bug952305-net-error

bug 952305
Merge pull request #15122 from staktrace/enable

Bug 909877 - Enable APZ for all of gaia. rs=milan
Bug 934657 - [Camera] Restructuring code following model / view pattern

Added abstractions to the Viewfinder view.
Cleaned up base View class.
Removed watch() from base View class.
Cleaned up some global 'enums'.
Initial view proposal
Changes following Diego's review
Moved event bindings out to AppController.
Refactored Viewfinder view to use the new View class.
Refactored Viewfinder view and Controls view to work with new View class.
Changed AppController to require() models instead of passing them through constructor.
Extracted CONSTANTS out into separate file and declared them as actual moz-JS style constants.
Added 'Format' util lib to eliminate need for the random 'padLeft()' function that currently lives in camera.js.
Started implementing zoom functionality in the Viewfinder view.
Pulled out init function from camera.js and included hud initialization in main app controller.
Filmstrip now AMD module
Introduce broadcast module to decouple hud from camera