#2419: agc_rules loading defaulting to is_custom true instead of false

git-svn-id: http://svn.osgeo.org/postgis/branches/2.1@11758 b70326c6-7e19-0410-871a-916f4a2858ee
#2414 extension not installing census tables

git-svn-id: http://svn.osgeo.org/postgis/branches/2.1@11760 b70326c6-7e19-0410-871a-916f4a2858ee