Somewhat imrprove balloon default position handling.
Merge branch 'balloon' into dataSourceBrowser

Conflicts:
	Source/Widgets/Viewer/viewerDynamicObjectMixin.js
Add double-click support to DataSourceBrowser items.
Fix crash.
Merge branch 'balloon' into dataSourceBrowser

Conflicts:
	Source/Widgets/Balloon/BalloonViewModel.js
Merge branch 'dataSourceBrowser' into uberbranch