Try to write a water-like better shader for sand. #91
New sand shader. Currently, it depends on the pixel position, so a particle-position-dependency would make a huge improvement. #91
use glsl clamp with float values #91
improve the sand particle appearance, matching the sand texture #91
Merge pull request #136 from lanice/Sand_91

Sand 91
Merge remote-tracking branch 'origin/master' into steam_element_130

Conflicts:
	shader/flush.frag
	shader/particles/material.frag
don't try to play element sounds if they don't exist #80