Reimplement WMS support from http://drupal.org/node/67291

(documenation from ripped out wms support)
  wmss - an array of WMS services arrays.  Each WMS service array can have the
    following elements:
      'name' - the name of the custom map (no spaces or special chars).
      'url' - the url of the WMS service.
      'format' - image format to retrieve. Depends of WMS service:
         'image/gif','image/png','image/jpeg'
      'layers' - a comma separated list of layers advertized by WMS service
         to show in this custom map.
      'minresolution' - lowest zoom level of this custom map.
      'maxresolution' - highest zoom level of this custom map.
      'copyrights' - an array of copyrights to display. Each copyright array
         can have the following elements:
           'minzoom' - lowest zoom level at which this information applies.
           'bounds' - a comma separated list of coordinates defining a
              region to which this copyright information applies: 'S,W,N,E'
           'text' - text of the copyright message.
      'overlaywith' - (optional) overlay WMS layers with this Google layers:
         'Map', 'Hybrid', 'Satellite' or 'None'(default)
      'merczoomlevel' - (optional) zoom factor of the google map where WMS service
         should advertize layers in Transverse Mercator projection instead
         of WGS84 projection. See discussion of this topic here:
         http://johndeck.blogspot.com/#112679047816546118
      'opacity' - (optional) Opacity level for this tile from 0.0 (transparent)
         to 1.0 (opaque)


-- This might not make much sense in this day -- Tile caches are much more common, and are simpler to get working...