added specular term
added rainbow cycling shader
made spec its own light
syncing with master
syncing with master
sync with master
cleanup
Merge branch 'rainbow-tex' of https://github.com/meetar/tangram into meetar-rainbow-tex
hsv2rgb2 -> hsv2rgb
reset default building rendering mode
Merge branch 'meetar-rainbow-tex'
Merge branch 'specular-dev' of https://github.com/meetar/tangram into meetar-specular-dev
small cleanup/tweak on specular light shader
add switch for specular light in lighting wrapper
add switch for specular light in demo
update build w/specular light
Merge branch 'meetar-specular-dev'
Merge branch 'master' into envmap