Corrected bug whereby sample was off by -1; set failures in SetImage (Lrs) and...

Corrected bug whereby sample was off by -1; set failures in SetImage (Lrs) and SetUniversalGround (Hrs) to unique special pixels

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@1793 41f8697f-d340-4b68-9986-7bafba869bb8