These components should NOT be on the palette:
===============================================
MediaController    -      This component should be instantiated in code. Does not work when included in XML.
Gallery            -      This component was deprecated in API level 16
ExtractEditText    -      This component is a specialization of EditText rendered on devices in landscape mode.
TwoLineListItem    -      This component was deprecated in API level 17.
Leanback fragments -      Need extra work to make sure these make sense.

The following components were removed because they're considered obsolete
(not commonly used, and just adds clutter and confusion to the menu) :
- GestureOverlayView, DialerFilter, ZoomButton, ZoomControls, AnalogClock, DigitalClock

TODO: Consider removing transition widgets.
