Get rid of `z-index: 1` which can cause layout problems.
Tweaks to the CSS on the top-right toolbar.
Merge pull request #1271 from AnalyticalGraphicsInc/no-z-index

Get rid of `z-index: 1` which can cause layout problems.
Merge pull request #1272 from AnalyticalGraphicsInc/top-css

Tweaks to the CSS on the top-right toolbar.
Streamline Context.draw
Merge branch 'ddr' into gltf