Issue #67: Create MetaData database to cache YouTube Trailer Info

In order to help with performance, particularly in Grid view, it is necessary
to cache the results from prior YouTube Queries for the trailer information.
The first time the the movie is queried, the metadata information is fetched
from YouTube, all future queries will access the cached information in
the sqlite database.

This has been implemented for both Grid View and detail views.
Issue #167: Subtitle Selection for Grid View

Subtitles can now be selected in Grid View if they are available.  This is
accessed through the context menu and then selecting the Subtitle Selection
option.  A new dialog opens with the available subtitles.
Set version to 56
Issue #179: Update Readme with clearer instructions on how to build the app

Thanks to AlBundy33 for the updated instructions.