This patch adds a button to toggle between normal and "diplomacy" colors.
- When playing, players are colored according to your stance towards them: green are allies, yellow are neutral, red are enemies, and blue is you.
- When observing, players are colored according to their team.
There are lots of things that need color, hopefully I've found them all.
There would be an OOS error if diplomacyColor in Player.js was serialized, so I removed that.
I made the button from minimap-idle.png, icons/minimap/zoom.png, and icons/diplomacy.png. It's fine if someone wants to make a better one.