Synced up succession laws

I removed the tanistry restrictions and reformatted both files so they
should be easier to update in the future.
Minor factions cleanup

Mostly formatting improvements, but also brought them up to speed with
latest vanilla fixes.
Minor CB updates and cleanup
Minor event updates and cleanup
Updated decadence events

Added the latest vanilla features and updated the holy order section to
properly account for VIET religions
Updated PB+VIET

Just updates and cleanup
Removed two PB+VIET files

After updating, these turned out to be identical. In the case of the
e_byzantium stuff, it's because the additional check to see if you were
the Byzantine Emperor is unnecessary. The game counts you as your own
liege when you're top liege.