LibreOffice from Collabora OS X

CPOSX.conf: --with-package-format=dmg
CPOSX.conf: re-add 'el'
CPOSX.conf: re-add 'sr-Latn' and myspell dicts
Multilingual Mac OS X DMG for Collabora

Change-Id: Icfa638141e99af3ba313cf235228fbab8b3594d2