Updated Greek MythFrontend translation from Yianni Vidalis

Thank you Yianni!

Refs #11848

Signed-off-by: Nicolas Riendeau <nriendeau@mythtv.org>
New Greek/Greece locale file
from Yianni Vidalis

Thank you Yianni!

Refs #11848

Signed-off-by: Nicolas Riendeau <nriendeau@mythtv.org>
Add a new MythZoneMinder date format