Corrected an inverted x/y coordinates bug.  Still a y/-y inversion bug remanining
Reverse y axis between SDL and bOoM rectangles.

Looks useless as apparently, in SDL2, y axis is reversed from SDL1.
No inversion should have be done at all.

rectangle now uses x,y,w,h (stored in two real2 v and s) rather than top,left,bottom,right.
Bug correction in the Entities and in the line-aabr intersection.

Beware the mouse input events seems to believe the origin (0,0) is at the bottom left of the screen.
Added motion of the view window by right clicking.