Preliminarily add noise JS module

Add NoiseJSM singleton object, and move Noise.player into it.
Move 'enabled' pref control and observer to JSM
Move play, log and RDF related methods to JSM
Move per window observerServices to JSM singleton
Merge branch 'jsm'
Ref #3 Add download topics for Fx 26

noise-dl.add
noise-dl.remove
noise-dl.stop (data: 'succeeded', 'canceled' or 'stopped')
noise-dl.error (data: code of error.result)
Fix nsITreeView error messages in Events Guide

nsITreeView getCellProperties changes, same as commit:436f990
Add Fx 26 download events to Event guides

Also detect Fx version, prevent expired event settings from loading.
Add new dl translation items to all locales
Prepare 1.3 alpha release
Merge branch 'download'