Keep pointer within window on maximize/fullscreen toggle

Spawn a window, maximize it in any way, move the cursor to a window border
that is not on the screen's edge and unmaximize again:  While the window
goes back the cursor stays at the screen's edge, i.e.  focus is lost to the
underlaying window.

Moving, resizing, tiling or snapping windows in any way always moves the
cursor along iff needed, e.g. using MS-[hjkl] to move a small window from
the center to the edge keeps the cursor within window borders -- no matter
what you do with the keyboard, focus stays on that window.

Make CM-f, CM-m, CM-equal and CMS-equal (default bindings) for toggling
full-screen mode, maximization, vertical maximization and horizontal
maximization of the current window drag the cursor along if needed as well.

OK okan kmos dv