Add a particles generator.

(Not used & texted yet, wait for the 'world' structure)
Add pictures for particles, fix generation of packed textures.
Add a world structure, add the particle shader, fix some errors.
Merge branch 'master' of github.com:needs/anko

Conflicts:
	src/client/shader.c
	src/client/shader.h
	src/client/ui/ui_game.c