ENH: prefer executable CLIs by default

This resolves a known issue with the application crashing while using modules
as shared libraries under certain circumstances.

Motivated by this thread:

http://slicer-devel.65872.n3.nabble.com/Slicer-crashes-when-running-registration-without-having-settings-set-to-quot-Prefer-Executable-CLIs--td4037245.html

git-svn-id: http://svn.slicer.org/Slicer4/trunk@25404 3bd1e089-480b-0410-8dfb-8563597acbee