Re-work how material uniforms are updated.
Remove need for context at material construction.
Fix tests.
Fix another test.
Use a texture cache.
Update CHANGES.md.
Added return to CompositePrimitive.add
Fix #1177.
Changes per review.
Further review.
Polygon doc and examples
Fast tests by default
Fix JSHint
Changes after review.
Fix test
Fix markdown formatting
Merge pull request #1182 from AnalyticalGraphicsInc/materials

Materials
Merge master to polish
Minor doc fix.
Merge pull request #1187 from AnalyticalGraphicsInc/polish

Hackathon polish