Convert locations for cap export.

I've stepped through the xml_post_render and it's doing the conversions, but...

1) gis_location records have been completely flattened out of the CAP hierarchy.  In the s3xml element tree, they are directly under <s3xml>.  So they are not found in cap/export.xsl.

2) wkt is being stripped from gis_location records.  So polygons are not getting their actual wkt, but only the fallback bounding box that I generate in xml_post_render.

I'm going to comment out the removal of the wkt field, so I can check the conversion of actual POLYGON wkt.