Fix channel store requests.

Fixes plexinc/roku-client#28, among other things.

It turns out that we really can't make a single channel store request, or make
two simultaneously. So we're making them serially now. We're also exempting
the old firmware, since we can't figure out if the user was grandfathered, and
sideloaded channels.

** ljunkie - just keeping RARflix in tune with Official
             Store is not applicable for now

Conflicts:
	Plex/source/AppManager.brs