Day 6 - Action!

I can now load a level, show the units in that level, and display an icon above the cursor that shows the action the player can do.

There's a lot of ugly if/then/else conditions in my code, but I'm not aiming for code beauty here :P
I'll refactor them in the postmortem anyways.

I also got the movements and upgrade working! I can select units, make them move, and spend coins to upgrade them.
I faced some "Out of bounds" exceptions, especially one tile that makes the game crash if you try moving on it. I don't know why yet, I'll have to investigate...

This is coming along pretty nicely. I thought I was late because I only started the jam on Monday, but I guess I may get it in time if I keep the mechanics simple. I'm thinking about using unit level as health (hitting an enemy unit decreases its level) because I don't think I'll have time for health and attack points.

Fun fact: before I disabled the ability for the cursor to wrap around the screen (passing the right side of the screen brings the cursor back on the left side), it was possible to teleport units through the borders of the screen... What a sneaky move...