PROG Outputing the statistics revealed an uninitialized value that was causing...

PROG Outputing the statistics revealed an uninitialized value that was causing tonematch's test to break. In tonematch, added the MINCOUNT option to allow the user to determine how much of the images need to overlap for the overlap to be considered valid. References #1383.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@5694 41f8697f-d340-4b68-9986-7bafba869bb8