Start of Viewer widget mixins.
Ongoing Viewer mixin work.
Ignore mouse clicks on the object we are already tracking.
Spec cleanup.
Merge branch 'viewer' into viewer-mixins
Minor doc tweak.
Merge branch 'viewer' into viewer-mixins
Clean up documentation.
Merge pull request #853 from AnalyticalGraphicsInc/viewer-mixins

Viewer mixins