Merge pull request #3 from playcanvas/master

update myself
Fixed shadowing artifacts on skinned models, added fresnel. Specular is now disabled when it's set to 0.
fixed overbrightening reflection issues when not using fresnel
Merge branch 'shader-system' of https://github.com/guycalledfrank/engine into shader-system
removed reflection calculation when not using any specular
Merge pull request #52 from guycalledfrank/shader-system

Fresnel support for Phong material plus some other GLSL fixes.