Changed to no longer extract points without a measure in CUBELIST when...

Changed to no longer extract points without a measure in CUBELIST when CUBEMEASURES is enabled, such that only points with a measure in CUBELIST will get extracted when CUBES is enabled, regardless of any other options that are set.  These changes fix #549.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@3625 41f8697f-d340-4b68-9986-7bafba869bb8