closeRing() method added in CoordinateList class

Patch by Vishal Tiwari <hi.vishal123@gmail.com>

git-svn-id: http://svn.osgeo.org/geos/trunk@3849 5242fede-7e19-0410-aef8-94bd7d2200fb
Fix CoordinateList.closeRing() use of past-the-end operator

git-svn-id: http://svn.osgeo.org/geos/trunk@3850 5242fede-7e19-0410-aef8-94bd7d2200fb