Add an animation to provide feedback for asynchronous CZML loading.
Different loading animation, not English-specific.  Better?
Merge branch 'master' into viewerLoading
Make loading indicator non-blocking.
Better centing for loading image so that it doesn't disable viewer UI.
Fixes after merge.
Merge remote-tracking branch 'origin/master' into viewerLoading
Use `absolute` instead of `fixed`
Merge pull request #384 from AnalyticalGraphicsInc/viewerLoading

Add an animation to provide feedback for asynchronous CZML loading.