UI update

Second release of our game (v0.1.1): focused mainly on UI improvements.

Release Notes:

• proper UI scaling
• menu button for fullscreen toggle
• expanded player HUD:
  • hp bar moved to top left corner
  • cubes layout
  • highlighted active cube
  • cube cooldowns
  • dash cooldown
  • gun cooldown
  • incoming damage direction
  • active gun icon

Behind the scenes (updates):

• using custom .mesh file format instead of .obj for storing meshes

See also:

release on GitHub: https://github.com/pwalig/3D-FPS-OpenGL/releases/tag/v0.1.1