BUG: Fix backwards compatibility for DICOM plugins

Fixed issue discussed here:
http://slicer-devel.65872.n3.nabble.com/DICOM-plugins-are-not-called-td4033045.html
Now the DICOM plugins that don't use the new naming of the plugin functions (examine was renamed to examineForImport to avoid ambiguity due to adding examineForExport) work without any changes.


git-svn-id: http://svn.slicer.org/Slicer4/trunk@23825 3bd1e089-480b-0410-8dfb-8563597acbee