ENH: enable using the picking manager

Turn on the picking manager on the interactor when creating the first
fiducial, ruler, ROI.
Only for VTK6, solves the issue of picking fiducials in placed order
rather than 3d depth order.
Dragging fiducials near other ones will sometimes cause a jump, but now
the 3d glyph position and the MRML node location stay in synch.

Issue #3319

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23178 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Add support for conditional upload to extension driver script

By default enabled, this option will allow to disable the upload of
extension while testing if they can be built.

This will be particularly useful when setting VTK6 dashboards for
the extensions.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23179 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Improve check for usage of ConfigurePrerequisites component

This commit ensures that no false error will happen by checking if
the variable CMAKE_PROJECT_NAME (set only by the project() command)
 is defined.

More particularly, this will avoid getting error while build the
VMTK extension.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23180 3bd1e089-480b-0410-8dfb-8563597acbee