Bug 790732 - Fix two more toolkit tests. r=me

Not sure why these didn't appear on earlier try runs, but they're trivial.
Bug 790732 - Remove the aTarget parameter from AttachComponentsObject. r=mrbkap

I added this when I thought we'd be defining Components on an object on the XBL
scope chain. At this point, it's not necessary anymore.
Bug 790732 - Stop attaching Components in InitClasses. r=mrbkap

This method is larely deprecated. The only two consumers are JSD and the setup
for the safe JSContext, neither of which use system principal and thus neither
of which should have |Components|.
Bug 790732 - Remove Components warning and Telemetry. r=mrbkap
Bug 790732 - Omit Components object for content scopes. r=mrbkap