Quick fix for Mongolia

Mayan Obsidian Warrior overhauled. The Spearman-to-Longswordsman upgrade path caused the Mayans to become needlessly dependent on Iron. It is now a Swordsman that has a 50% anti-mounted promotion. This allows the Mayans to retain their basic defensive units, while providing them with a stronger alternative if they have access to Iron.

Aztec Sacrificial Altar now yields 2 happiness instead of 1.
Viking Longhouse now gives all melee units a 15% combat bonus when attacking, supporting a Domination Victory.
Iroquois Rusher now ignores movement costs instead of having 3 movement. (This means that they can't sprint over flat terrain anymore, but instead aren't slowed by rivers).
English Playhouse now has free maintenance instead of +2 culture.
Mongolian Ger now gives units the Cover I promotion instead of 10 xp.
Portuguese Casa da India now yields 8 gold instead of 4 (since it can only be built once).
Ottoman Hamam now yields 3 Happiness instead of 2 (since it can only be built in some cities).
Oromo Warrior no longer gets extra XP from combat (the two free promotions were enough).
Indian Sepoy now gets extra XP from combat (because the free Siege promotion wasn't enough).
Polynesian Koa now has a higher combat strength (16 instead of 14).
Persian Dar-be-Mer no longer has maintenance.

Now compatible with Single Unit Graphics mod.
Mongolian Yam now replaces Stable instead of Caravansary (this makes it compatible with Improved Caravansaries mod). Yields altered to balance.
Byzantine Hippdrome no longer uses up a Horse resource (it was competing for resources with the Cataphract UU). Now requires a source of Horses or Ivory like a typical Circus. Removed +1 Gold yield.
Spanish Mission no longer gives Missionaries +1 usage of Spread Faith. The 25% passive spread bonus is strong enough.
French Salon now replaces Zoo instead of Windmill. Yields +2 science instead of 10%. This is to encourage building a wide empire.
Shoshone Tipi yields +1 Culture and +1 Production by default (+1 Culture bumped earlier for simplicity's sake). Construction time increased.
Ottoman Siege Foundry removed.
Ottoman Great Bombard UU (Cannon) added.
Improved artwork.

Small tweaks and improvements

Converted XML files into SQL files. (This makes it compatible with almost every other mod).

Small tweaks.

Visual improvements for some icons.
Shoshone Tipi yields changed - Now yields Production instead of Food. +1 Culture bonus moved to Drama. +1 Culture at Archaeology unchanged.
Polish Barbican yields changed - Now yields additional Food, which is replaced with a Culture/Tourism bonus upon Flight.
Roman Thermae yields changed - Removed +2 Food and replaced with +1 Culture. +1 Science unchanged.

Small changes and tweaks.

Replaced American Saloon with American Ranch

Changed Aztec Eagle A.I. to make better use of abilities.

HUGE MEGACHANGES CANT LIST THEM ALL

Replaced Zulu Kraal UI with Zulu Kraal UB - Too many reports of textures not loading. Buffed Polynesian Fish Pond. Fixed problem with Spanish Bullring replacing incorrect building.

Minor tweaks, attempting to fix the Zulu Kraal incorrectly rendering.