Update NEWS for 1.11.1

git-svn-id: https://svn.osgeo.org/gdal/branches/1.11@27732 f0d54148-0727-0410-94bb-9a71ac55c965
Update version numbers for 1.11.1

git-svn-id: https://svn.osgeo.org/gdal/branches/1.11@27733 f0d54148-0727-0410-94bb-9a71ac55c965