Ok, so as the title states, have the Papal States survive up to 1900, preferably. By "survive" I mean that it must be a sovereign theocratic state, capable of handling its own defense, government, and economic matters. Furthermore, it must be larger in territorial size than at least modern-day Montenegro. Bonus points if it's larger than today's Macedonia. More bonus points if the rest of Italy unifies around it. Even more bonus points if it can be done with few enough butterflies to still allow WWI to take place somewhere in the 1900s-1910s.