Complete improvement of geos-implemented error message from postgis

These ones did not match my previous regexp :)
See #2970

git-svn-id: http://svn.osgeo.org/postgis/trunk@13106 b70326c6-7e19-0410-871a-916f4a2858ee
Fix typo in "make garden" output summary

git-svn-id: http://svn.osgeo.org/postgis/trunk@13107 b70326c6-7e19-0410-871a-916f4a2858ee
Allow running "make garden" over an existing "postgis_garden" database

git-svn-id: http://svn.osgeo.org/postgis/trunk@13108 b70326c6-7e19-0410-871a-916f4a2858ee