Update materials API
Merge pull request #30 from shama/textures

Update materials API
0.5.1 - small fix to make it work on the server again
0.5.2 - make meshing algorithm configurable
also use new greedier mesher
s/greedier/greedy
0.5.3 - switch back to 'greedy' mesher
playerHeight option
add some more docs to the readme
Add `fogScale` and `skyColor` options.

skyColor determines both the colour of the background and the
colour of the fog - it looks nicer when these two match.

fogScale will scale the fog distance by game.worldWidth()
Merge pull request #36 from hughsk/skycolor

Add `fogScale` and `skyColor` options.