PROG OS truth data was being ignored due to the tsts make file not knowing the...

PROG OS truth data was being ignored due to the tsts make file not knowing the OS information... this fixes that. This was caused by the Squish Coco changes which prompted a quick refactor of a couple of make files. References #1044.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4640 41f8697f-d340-4b68-9986-7bafba869bb8