Hotfixes and Quick Wins

Some of you told me about some bugs I had to remove and I took the chance to add some quick wins too:

• Promotion didn't work
• Pawn could always go 2 fields on their first move
• You now can move units with one right click or the old way with two left clicks
• Overworld UI got a new style
• Graphic reworks for trees, stones and shadows in general