I made a mess with the licence. Now the LICENCE file should contain only the necessary and the sources should start to contain the reference, (i was lazy about that).
I considered the fact that this program is using a huge library (like sdl2) for a rather small task. I want my software to do a lot of fun stuff, but most of this stuff is calculations and data management. What SDL2 is task for is to put a plane, set a grid and display entities in the correct position.
I'm working on it on my free time and probably in the next few weeks I should be able to do the changes i have in plane to develop.