[todo] Todo example.
[threads] More tag functions.
[client/params] Default to grabbing the parameters from the environment if they aren't provided to the constructor.

Fixes T368
[examples/todo/server] Update the APIClient import on todo server example.
[APIClient] Better handling of request errors.

Fixes T361
[client/interface] Switch the filters over to use kwargs to be more pythonic and clean up the interface.

Fixes T369
[examples/todo/server] Update to new interfaces.