Fixes the hardcoded http which was causing cesium not to load over https

Fixes 2719
cherry-pick from PR 139
From another cherry-pick 2a439220c8a1b731c3a18af73d7f13aecddd3173
From cherry-pick 1efb2e9788df5fb51a6c27d54a46494b29abcf42
Adds line endings to make sure these files should load on each OS
Updates for API changes in b30
Updates the image and terrain providers
Updates the Cesium Viewer to the latest version
Fixes the reference to the ellipsoid
More b30 API changes
Fixes the czml demo
Updates for another API change from b30
Attempts to update the Cesium.Widget object
Checks the camera type before calling the pick
- remove support for layered sounds
- refactor/clean up volume controls
- actually make it work
Makes the pick call recursive
Adds a check for the masterVolume being undefined
- fixed the initialVolume setting.
Rewrote the sound group functionality.  There is now a first-class
object for each sound group with a lot more built-in code.

This may have finally fixed the bug where we get multiple VO playing
at the same time.  I hope.  However, it may have introduced a new bug
where VO doesn't play.  I've left a fair amount of debug logging in.
If VO is missing (or if you see any error messages), please save the
log and send it to me.