Fixed bug with deleting pts from navtool and added check box to setarpriori...

Fixed bug with deleting pts from navtool and added check box to setarpriori for calculating surfact pt.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@2865 41f8697f-d340-4b68-9986-7bafba869bb8