Added new keywords to the log summary of cnetextract: Input/Output...

Added new keywords to the log summary of cnetextract: Input/Output Points/Measures, for the purpose of reporting to the user how many of the original points and measures were extracted to the output.  A bug was fixed in the Latitude range check, and an exception will now be thrown if the user provides a minimum latitude greater than the maximum latitude.  Both of these changes fix #251.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@2883 41f8697f-d340-4b68-9986-7bafba869bb8