New small tool: Color Markers

Hello again! 

I've been hammering some small changes to make a new update for the tool. Now, in coloring mode, you can color over the tiles in the map. This is useful to show the shape of attacks, area of effect or if you just want to drive attention to something in the arena.

Additionally, I added some key shortcuts to the option menu (Esc) and the help sections (F1). Also some small fixes.

Enjoy!