Add minimum_version to <Map>. Recent mapnik builds will throw an error notice if the mapnik version is older than minimum_version.
Add minimum_version to <Map>. Recent mapnik builds will throw an error notice
if the mapnik version is older than minimum_version.


git-svn-id: 73c701e01722c46394f20a5454405c8494da0091@19506 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4

Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets,Nithanaroy/mapnik-stylesheets