Added profiling command line flag
ModularProgram now correctly triggers ModularVisual.update
give SceneCanvas symbolic Entities to represent ndc, fb, and lpx coordinate systems
Break scene.transforms into subpackage
Merge branch 'transforms-subpackage' into transform-cache

Conflicts:
	vispy/scene/transforms.py
Implemented basic transform caching; testing needed.
Corrections to SceneEvent transforms
Fixed transform issues; more testing needed
Fixed transform cache handling
Optimization
Fixed bugs