Merge pull request #85 from thefinestsieve/beta

More event picture tweaks
Fixes for Muslim Invasion CB

A few fixes. It also conforms with the vanilla diff whenever possible now.
Caliphal subjugation now valid for Yazidi
Obligatory changelog trailer [Yazidi Caliphate now may Subjugate]
Merge pull request #86 from zijistark/dev

Fixes for Muslim Invasion CB
Imperial reconquest tier decisions