init outline
Merge branch 'master' into corridorOutline

Conflicts:
	Source/Core/CorridorGeometry.js
finish merge
clean up wall indices, add tests
sandcastle example
Shader builtin functions/structs/constants broken into individual files. ShaderProgram.js now only concatenates builtins that are referenced from the particular shader being compiled.
Clean up glsl->JS script
extracted automatic uniforms into their own file
Fix shader typo
Shader builtin functions/structs/constants broken into individual files. ShaderProgram.js now only concatenates builtins that are referenced from the particular shader being compiled.
code cleanup
generate a dependency graph for determining which built-in functions/structs/constants to include and the order to include them in
preserve the number of line breaks when stripping glsl comments for dependency determination
check for circular dependencies in built-in functions.
added back shader uniforms and constants after merge
Merge branch 'master' into corridorOutline

Conflicts:
	CHANGES.md
clean up from merge
Code cleanup
removed czm_ prefix from cesium glsl built-in files
new shader test