Crash-fix Agony ver:0.9.3a

- fixed crash on leader-army swap
- applied missing "clears" for unwanted scripted invaders
- balance rebellions between sherden and peleset

Released Agony ver:0.9.3

Sea Peoples
- Sherden and Peleset factions became playable again
- Sherden and Peleset now own 1x starting region
- Sea People armies now spread sea people culture into residing and adjacent provinces
- Sea People are now settled factions
- a new building chain is available to all factions in coastal settlements which invites sea people
-- buildings of that chain add base resources and increase sea people culture in the region
-- AI likelyhood of constructing that building depends on their culture

Sea People Rebellions
- rebellions that are composed of a majority of sea people units will now belong to either the Sherden or Peleset faction and therefore naturally increase sea people strength
- sea people rebellions will happening in player home regions that are owned by other factions (no more armies spawning for the player)

Other
- if the population size for a unit category is met to generate a new unit but the rolled unit tier/rarity does not exist, then a portion of that accumulated population will be shared among the other unit categories (to have less chance of high tier cav to become available before the required tier chance is reached)
- various smaller fixes to e.g. spawning AI faction leaders