Bulgarian Revolt improvement

If the Bulgarian Revolt is destroyed completely the land once more
becomes dejure Byzantine
Bulgarian Unrest improvement

If a Bulgarian ends up on the Byzantine throne for a period of more than
a few years the Bulgarian Unrest will end
Holy Order vassals

The Knights Templar and Hospitaler now start as dejure vassals of
Jerusalem
Merge branch 'beta' of https://github.com/Meneth/PB-git into Meneth-beta