add shaders to makefile
remove some shader cruft
splitting some shaders into functions
add glslify
start moving some shader functions to glslify modules
standardize glsl var naming: u_ for uniforms, a_ for attributes
standardize glsl var naming: v_ for varyings
move shader lighting functions into glslify modules
move depth re-scale of Z coord to glslify module, and fix pop-up projection
update package.json
Merge branch 'master' into glslify

Conflicts:
	package.json
pull z layering scale factor into an external constant
directional light doesn't need vertex position
split height-based lighting boost into its own function
commented out point rendering for testing
add shader modules to makefile dependencies
move tile view & world transforms into matrix uniforms (using gl-matrix)
comment out some currently unused uniforms
split projections into perspective, isometric, and popup glsl modules
tweak depth calc shader module
simplify point shaders w/new modules & matrix