Adjusted some weapon entries to be more consistent across the roster.

Fixed wrong bow animation entry for etruscan archers.

Fixed missing unit card for garrison slingers.

Fixed missing population script entries for new units.

Fixed some inconsistencies with custom battle unit permissions.
Created new unique etruscan slinger and javelin units so italian factions can use the generic DeI italian units.

Updated RotR / GC units to have more appropriate and varied helmets.