Added automatic environment setup that works with every Isis 3 application....

Added automatic environment setup that works with every Isis 3 application. The automatic setup is setting the Qt plugin path. Fixes #742.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@4085 41f8697f-d340-4b68-9986-7bafba869bb8