End of the grid module and a test of it

I just finished my grid module, it allow you to create a grid with the
number of column and case you want, with case Object where you can add
the properties you want for you game.
In the test I also use the mouse module to select a case.
Test of the shooter with image
Merge branch 'master' of https://github.com/plancien/learning-engine into optim-code-Tibo