Additional Map Editor Commands

Hey Devs, really enjoying your game!!! I'm especially enjoying the map editor.

I have a few recommendations for the map editor.

One would be to add an "undo last command" option.

Another would be to add a hotkey that would force your mouse along a line, for example holding control while moving the mouse would move the mouse in a straight line, making it easier to extend in one direction.

A final recommendation would be a hotkey that shows the coordinates of the cursor on the map. This would make finding the center of the map easier. Could also have a red cross or bordered square that highlights where the center is.