Start of CesiumViewerWidget replacement.
Merge branch 'master' into viewer
Use buildModuleUrl instead of require.toUrl.
Merge branch 'master' into viewer
Merge branch 'dataSources' into viewer
Expose data sources collection and drive the display.
Ongoing Viewer widget work.

Add ability to control which widgets are created at construction time.  Also properly implement destroy and clean up some Timeline code to allow it to be destroyed.
Merge branch 'homeButton' into viewer

Conflicts:
	Source/Widgets/BaseLayerPicker/BaseLayerPicker.js
	Source/Widgets/FullscreenButton/FullscreenButton.js
	Source/Widgets/lighter.css
	Source/Widgets/widgets.css
Make Viewer use HomeButton widget.
Merge branch 'homeButton' into viewer
Start implementing specs for Viewer
Specs, documentation and cleanup for Viewer widget.
Add billboard rotation and aligned axis.
Merge branch 'dataSources' into viewer
Merge remote-tracking branch 'origin/master' into viewer
Merge branch 'dataSources' into viewer
Add helper function for drag and drop with the new Viewer.
Merge remote-tracking branch 'origin/master' into viewer
Specs for drag and drop and other misc Viewer work.
Ongoing Viewer work.

This change primarily adds back functionality to the Cesium Viewer that is now considered app specific, in this case, the existing query parameters.  Also made a few other tweaks.