More bug fixes after review.

1. Fix a bug in the Ellipsoid visualizer that was found while investigating another problem.
2. Fix a bug in Path visualization where we would evlauate a point outside of its availability.
Remove ReferenceFrameTest.czml.
Added mention of new classes to CHANGES.md.
EOP doc improvements from review.
Put Transforms variables closer to where they're used.
Add tests of exception and undefined cases.
Merge remote-tracking branch 'origin/master' into icrf
Converted ViewportQuad to use the material system
Some doc and cleanup
More doc and cleanup
Put sub-suites in the same category as their parents.
Merge remote-tracking branch 'origin/master' into jasmine-usability
Fix some missing target='_top's (needed for following links inside coverage)
Implement simple texture mapping as an alternative to using the material system
Update to ViewportQuad doc example.
Added emission component to final material color.
Initial ViewportQuad test
Removed picking code
Merge branch 'master' into playback

Conflicts:
	CHANGES.md
fixed ViewportQuad tests
Merge remote-tracking branch 'upstream/master'

Conflicts:
	CHANGES.md