Added FunctionChain class needed for transforms
Avoid repeated updates when setting chain list
Moved function2 -> function
Made most important names importable from vispy.scene.shaders
Transforms appear to be working.
Transforms appear to be working
Most places import from vispy.scene.shaders now
Merge remote-tracking branch 'almarklein/glsl-function' into glsl-function-transforms

Conflicts:
	vispy/scene/shaders/function2.py
fixed shader variable update with numpy arrays
Can now update uniforms without triggering recompile
line_visual2 example demonstrates ability to update transforms without recompile
Minor edits / fixes
Merge pull request #4 from lcampagn/glsl-function-transforms

Glsl function transforms