doc: define class wth_connection
doc: define class wth_connection

Group all wth_connection methods under the class. The function that
should probably not be public are marked as private, it seems they get
omitted from the Doxygen docs.

Signed-off-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

waltham/waltham,waltham/waltham