The following were also done as part of this commit.
 - Disable SelectionControlToolbar.
 - Delete Undo Redo buttons from 3D view.
 - Move QueryData button to MainControlsToolbar.
 - Handle logic in a specilization of pqRubberBandHelper called
   pqSlection3DHelper.

The pqSlection3DHelper class does the following
 - Manages all selections
 - Ensures that only one selection is enabled at any given time.
 - Makes 3D interaction mode implicit.
 - Enables new behavior where selections can be pressed and released.

Change-Id: I831babf266780e3b490bf4defa1592d15d468ed6