Issue #118: Implement partial watched indicator.

This implements a partial watched indicator for the detail video view.
Fix typo for Options for french translation.
Issue #115: Support generic season and episode number format.

Plex does store and return the season and episode number information for
a video item, however it hides it.  Information is stored as the index and
parentIndex values.
Slight tweak to gallery background to make it a little darker.
Issue #116: Allow wrap around navigation in Serenity Gallery view with D-PAD

When navigating with the D-PAD allow wrap around navigation. If on the
first item, allow moving left and going to the last item.  If one the
last item allow moving right to jump to the first item.