Simplifies ShaderGraph inputs/outputs

- Now it's clear that nodes should not be helper
- Node must have input/output
- it's still not clear how to organize helpers in Compiler.js
Cleans new factory node system

- move gl_FragColor into data.js
- remove unused variable in Compiler
- fix registering of node in factory
Updates shader generator example
Fixes bug in Compiler

- fixes regexp issue in InlineCode
- add getAttributeType in Compiler
Simplifies code using getAttributeType
Fixes diffuseColor in lighting
Improves a little bit the shader node management
Updates gitignore
Changes the default behaviour when there is no lights
Prevents empty draw call
Merge pull request #193 from cedricpinson/feature/simplify-shader-generator-api

Feature/simplify shader generator api
Merge pull request #198 from cedricpinson/fix-empty-draw

Prevents empty draw call
Add osgShadow to osgjs
Adds shadowMap Sample
Fixes the world matrice issue
restore sample demo to shadow scene
Fix world matrix camera view index fix unit test
Uses shaderprocessor in updated osgShadow example
Formats files
- Updates Demo with lightSpeed and distance parameters