Service, adapters and serializers

The service is now partially implemented, I've replaced the registry with
adapters, and more serializers are implemented.
Service, adapters and serializers

This should have been in the previous commit, still need
to get used to GIT's 'add' requirement for files that
are already in the repo... :|
Moved tests to separate dir
Removed unused code.
Cleanups

Removed the 'serialize' method from Serializer (so, like, now they're
not serializers anymore, well, they weren't already anyway, just converted
to dicts :) so I'll rename later), moved all JSON conversion to jsonutils,
some smaller cleanups.
Meh, copy/paste issues.
Half-working event handling/server push

This contains an almost complete implementation of
the event handling mechanism and API that're required
for server push, but since the client decided to drop
the feature, and event handling turned out to be hairy,
it's not, and won't be anytime soon, fully working.
Removed anything related to events or push for now
Events removed, more generic AT-serializers

Removed more of the event/push mechanisms (which are not
going to be used, at least not in the first version),
made the AT serializer more generic by inspecting the schema
rather than letting the user define the fields to serialize.