Use adapted types for the different result types. This makes it
easier to have adapted output formatting and means there are only
result fields that are filled.
Most of the server implementation of V1 API now resides in
api.v1.server_glue. The webframeworks only supply some glue code
which is independent to changes in the API code.
Code is now organized by api version. So formatting has moved to
the api.v1 module. Instead of holding a separate ResultFormatter
object per result format, simply move the functions to the
formater collector and hand in the requested format as a parameter.
Thus reorganized, the api.v1 module can export three simple functions
for result formatting which in turn makes the code that uses
the formatters much simpler.
