[WIP] Add vertex buffer creation

This PR adds vertex buffers to surfaces and prepares the egl drawing to the monitor.

- [x] Get the monitor to display EGL things
- [x] Add the vertex buffer to surfaces
- [x] Add a global redraw loop
- [x] Make it work
I'm not sure what `cur_mon` is, is it a `ws_monitor`? If yes: I think you need read locking here...