Fix: Possible double free when resetting PGS subtitles.

This resulted in random crashes when seeking quickly in a file with PGS subtitles and other various cases.

Fixes #4240.
Update translations from Transifex:

 - Catalan
 - Croatian
 - Japanese
 - Slovenian
 - Spanish

Fixes #4268.
Add IPTV capabilities to the existing Digital TV UI

Signed-off-by: xpc1000 <xavier_portell@hotmail.com>