Everything better (OGL 3.3)

+ Add dake and make everything OGL 3.3
+ Load mesh
This is awesome

+ HDR
+ Use of HDR for center positioning
Background music

+ iei
It's... beautiful

+ Stars
Less stars (4096 -> 1024)

* Because less is more
Small fixes

* Normalize models to stay in a common bounding box
* Prevent "infinite" enlightenment (looks better with finite)
* Decreased saturation
! Stars get fixed depth (far away), so they don't occlude the main
  object
Clean up and fix AlRenderer

* Put static objects from gl_renderer.cpp into the class; also, make
  them shared_ptrs, so we don't have to worry about them
! Introduce init_with_context() to AlRenderer (analoguous to
  GlRenderer), so we don't attempt on loading sound data without having
  OpenAL initialized (relevant for tasks 4.1 and 4.2)
Simplify star non-occlusion

* Just clear the depth buffer after having drawn all the stars instead
  of fixing their depth in the shader (which is horrible)