Review: Mouse API step 1: sol.input and pressed/released events

One day I'll make you eat your rhetoric ;)

This allow me to make some test on an iOS quest using the mouse API without risking merge conflict or multiple merge commit as usual, until I finish the cmake generation of a proper iOS project.
As you know, I'm not a frequent git user, and this branch is supposed to be merged before the 1.3 release anyway.