Clean up WebGL debug messages
Use WebGL validation with tests using createScene. Use WebGL validation only when requested.
Fix JSHint warnings
Test workarounds for IE 11 DC1
Merge branch 'master' into more-ie11
Merge remote-tracking branch 'origin/master' into more-ie11
Merge pull request #1849 from AnalyticalGraphicsInc/more-ie11

More IE 11 fixes