Issue #131: Fix issue with subtitles not displaying

If automatic subtitle language selection was not set in the preferences
even if a subtitle was choosen it was not being sent to the players.
This was happening for both the internal and external players.
Set version to 1.3.8
Issue #131: Fix subtitles not displaying for Episodes

When refactoring occurred in 1.3.4 the subtitle dropdown would not
occur for Episodes.  This has been created.
Issue #131: Backport fix to 1.3.x series and update version number

Backports the Subtitle fix for episodes to the 1.3.x series and updates
the version number.