In qmos, newer project files will once again work with older versions of qmos...

In qmos, newer project files will once again work with older versions of qmos (isis 3.4.2 and earlier). Fixes #1478.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@5005 41f8697f-d340-4b68-9986-7bafba869bb8