Updated our Cube class to be closer to the current coding standards. This...

Updated our Cube class to be closer to the current coding standards. This change will not change how Isis behaves, any file formats, or any other output from Isis. Fixes #1356.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4941 41f8697f-d340-4b68-9986-7bafba869bb8