controller::engine: Use public inheritance

! Using public inheritance, this will work.
controller::input_event_handler: Use bits for mask

* Use explicit bit numbers to define the mask in
  controller::input_event_handler. This makes it more recognizable as a
  bit mask.
Headers: Include <memory>

! Using shared_ptr<> requires including <memory>. I'm forgiving about
  the implementations as they are including their respective headers,
  but the headers need this.
controller/logic.hpp: No newlines? windows plz

+ I want them (at the end of files)
view/glut_window.cpp: Use static_cast from void *

! Use static_cast from void pointers. There is no need for
  reinterpret_cast and some even say it is wrong to do so.
GlutWindow::glut_keyboard(): Fix mask generation

! Fix the mask generation for controller::InputEventHandler.
Remove uncommented artificial errors

- Remove errors which are to be thrown if certain areas are not
  implemented yet. They are already uncommented, but we don't need them
  at all (especially with having git as a VCS, we could always restore
  them if need be).