PROG: Updated Makefiles for cnetcombinept so that ControlNetworks will be...

PROG:  Updated Makefiles for cnetcombinept so that ControlNetworks will be output as PVL files (so that *pvl.DIFF can be applied for the truth-output comparison).  References #4870,4722,4869

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@7833 41f8697f-d340-4b68-9986-7bafba869bb8