Added bindings for SDL_WM_GrabInput to module sdl::mouse

[jaburns]

Although SDL_WM_GrabInput may affect the way keyboard events are handled, this was done in the mouse module since it's primary use is generally to capture the cursor without having to spam SDL_WarpMouse.

[lgrz]

Thanks for the patch. Although my understanding is that bindings are already available from within the wm module. Was there a particular reason you were not able to use the grab_input and is_grabbing_input functions provided there?

[jaburns]

Heh. Somehow I managed to skip the step of grepping the project for SDL_WM_GrabInput before implementing the bindings. Sorry to bother with a redundant patch!

[lgrz]

No problem