Clean up Main Menu and Moview Browser construction

The code was having everything happen in onCreate and onResume.
The problem here is that onResume is always called after onStart
which calls onResume, so the screens were getting drawn twice.

Restructured code to take into account better when the Gallery
needs to be refreshed as well as any spinners in use.  This provides
a noticeable difference in how soon the screen is available to be
used by the user.
Clean up TV Show Browser and Season Activity

Same issue as with the Main Menu and the Movie Browser states,
refreshing unnecessarily causing delays and states to not be
kept when returning to the activities from the previous activity.
Update Episode Browser Activity

Same issue as the other activities redrawing the screen too often.
Fix Force Close when Back Button and OSD showing.

The app would force close trying to update the progress bar information
if the OSD was showing and the back button was hit.  Handle this by
catching the Back keycode, stop the video playing, and then hide the
OSD display.
Issue #11: Implementation of Category Filters for Movie Browser

This completes the implementation of category filters for movie browsing.
Both the single level filter as well as the secondary filter are implemented.
A soon as an item is selected it either refreshes the poster gallery or
populates the secondary filter and repoluates the poster gallery with
the first entry.

Categories are all D-Pad navigable.