cneteditor can now save filtered networks; required fixes to CNet where copy...

cneteditor can now save filtered networks; required fixes to CNet where copy constructor was reordering measures in a CP and not correctly generating the CNet graph; this revealed problems in computations in the ControlNetStatistics class that have now been addressed. Fixes #619

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4314 41f8697f-d340-4b68-9986-7bafba869bb8