Increase epsilon values for failing tests.
More robust computation of tile edge planes.
Temporarily disable horizon culling.

It's not working correctly for the root tiles in Canary.
Fix more camera tests where code was producing NaNs.
Fix and re-enable horizon culling.
Clean up plane computation.
Update CHANGES.md.
Merge remote-tracking branch 'origin/master' into tilePlanes

Conflicts:
	CHANGES.md
Merge pull request #1387 from AnalyticalGraphicsInc/tilePlanes

Fix tile plane and horizon culling problems in Chrome Canary
Merge branch 'master' into canary-failures
Update comment.
Merge pull request #1386 from AnalyticalGraphicsInc/canary-failures

Fix Canary failures
Merge branch 'master' into balloon