Fixed a bug in the ProjectionFactory class which causes maps to have an...

Fixed a bug in the ProjectionFactory class which causes maps to have an unequal number of lines/samples from projections symmetric about the prime meridian or 0-latitude.  Fixes #2245

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@7109 41f8697f-d340-4b68-9986-7bafba869bb8