Geoparser form does not validate against cck field definitions

If more than one location is selected in the geoparser form, but the content type and field have been set up to receive only one value, the form silently adds only one value from the form. If the location field has been set as required, but no geolocations have been selected, the form silently fails.

Add checking against the defined field and content type to appropriately warn users if they have made a selection which is invalid.

See attached patch.