if i change maptype to osm, current maptype copyright stays at bottom
example:
http://www.mario-baldauf.org/API_v3/verortung/index.html
It loads with custom (OSM) mapType and no copyright information is
displayed. Switch to roadmap and Google copyright information is
shown. Switch back to OSM and Google copyright information is still
there.
I think it proves there is a working mechanism for the copyright
information but it is not documented yet.