Improve trading system (similar to PlayCatan)

Full requirements and images:
https://www.dropbox.com/s/0htsc0e52hf0of3/ColonistTradingSysDoc.zip?dl=0
Example flow video:
https://www.youtube.com/watch?v=PnIKGvv3fdg&t=17m55s
17:55 to 18:25

tl;dr: Make the trading system similar to PlayCatan:

1. Every player can offer trades to the active player. Even when the active player did not initiate. Players trade offer is displayed next to the player.
2. Both players have to click accept. All players see who has accepted a trade.
3. You can propose a trade that has nothing on the other side - indicating that the other player could counter-offer something similar.
4. Multiple decline buttons for easier communication. If everyone says 0, no point in offering trades etc.
5. Trading with bank does not interfere with trading with players - separate bank trade button.

Image: Some other UI changes displayed too: moved chat and log to pop-up window, roll history. Players displayed around the board - makes it more intuitive than a top-down display.