Additions to 3.13

Units upgrade to Swordsman and Composite Bowman with Renowned Warrior/Archer stories (may already be in?)
Unit upgrades is now 2 times production difference as intended
Walls now have 25% conquest propability as intended
Removed resouce requirements for Gatling Guns, Bazooka and Machine Guns as intended
Ceremonial Rites now give +1 culture/cultural Building as intended