from the app config file.

Also fixed some more tests.

Also fixed a typo in calling write() with a parameter.

The etcd interface now passes all tests and also supports a very crude
audit logging. At the moment, only 100 audit messages are supported.

Due to a change of behaviour in dateutil, we had to change a little our
exception handling in the schema in order to pass tests in python
2.7.5.

The etcd driver has still not been road-tested

of the client to decode datetime values

Before, we raised a configdb.exceptions.NotFound which could be confusing when debugging.

With a small change to preceding versions, now we use a "number" to store the timestamp data, as we need a little more fine-grain
and there is no reason to lose information at this stage.

Added the decorator for updating the timestamp of the last modification to
a group of entities. No global lock is in place so it may happen something
goes wrong under fast updates. However, we are keeping the timestamp with
seconds granularity right now.