Color corrections for Maya and China.

version 2 changelog:
- new colors assigned to Assyria, Brazil, Indonesia, Morocco, Poland, Portugal, Venice & Zulu.
- reassigned colors for Sweden & Huns, taking advantage of the expanded spectrum to better suit them.
- Shoshone takes the previously Hun light-green.
- Minor adjustment on the Iroquois' sand

Corrected wrong civ icons being displayed on AI city bars and other screens.