Minor update fixing an event that wasn't working correctly.

MAJOR UPDATE:
Added the Senatorial Republic, a republic loosely based on Rome or Carthage, in addition to a rework of estate disasters.

When burghers get enough influence, an event will fire that gives them a little bit more influence and less loyalty temporarily, combined with other factors though, this could lead to a Burgher coup.

When the burghers disaster happens, you have less than 1 stability and a revolt happens, it will cause the people to take control of the government, leading to the establishment of the Senatorial Republic.

The Senatorial Republic has several factions that are opposed to each other, when one faction like the ruler has 30 influence and the Senate for example has 50, or if one faction such as the ruler has 70 or more influence, it can cause a factionally based civil war, from which the government form may change to a Military Dictatorship, a Prussia like republic, a Peasant Republic, a Technocracy, or the ruler may consolidate power and turn the Republic into an Empire.

Modified MTTH for bad events-

Fixed a bug where each province in a plague would give 2 unrest, instead of the country plague modifier giving 2 unrest.

-Made the time for plague spreading shorter.

-Changed plague Mean Time To Happen modifiers for development and roads from 0.5 to 0.75 to make plagues a bit less common and spammy.