Upgrade of cgimap

The cgimap software that runs much of the OSM API was upgraded to the 0.6.0 release and the /api/0.6/changeset/NNN/download and /api/0.6/{node,way,relation}/NNN/history calls were switched from the rails code to cgimap.

Sarah Hoffmann stepping down from OWG

Sarah joined OWG in June 2013, and has decided to step down from the group. We would like to thank her for all her work in the group over the last 4 years. Sarah remains as a Sysadmin and continues to work on Nominatim.