Bug 1084098 - Pre: Don't require GeckoApplication in Themed*widgets. r=mcomella

In editors (Eclipse and IntelliJ), Android View sub-classes are created
in a "Bridging" mock context.  There is no ambient GeckoApplication in
this case.  It's already okay for the LWT to be null; let's loosen the
requirement that there be an ambient GeckoApplication to let these View
sub-classes render in editors.
Bug 1084098 - Adjust padding/margins of Sync tabs panel items. r=mcomella

Pretty straight-forward implementation of the mock.  The mock shows a
different "bookmark star" icon, with slightly different right-margins,
and implementing that change requires changing the TwoLinePageRow layout
to not use drawableRight for the star.  (Otherwise, the star will not be
vertically centered in the container.)  I don't care to make that change
for this ticket.
Bug 1084098 - Add Android tools tags to some Remote Tabs home panel views. r=mcomella

These tags are used by Android tools (including IntelliJ) at design-time
to show "sample data".  They're stripped entirely at build time.