Enaml-web

DB API was moved to an external project named `atom-db`

DB API was changed to use a `get_or_create` method that can work with caching
when restoring objets from the database. The serializer `find_object` was
renamed to `get_object_state` and takes the object created by `get_or_create`
instead of the object class.

Add option to define order when restoring state by tagging members with
a `setstate_order=<number>` to used for sorting. The default is `1000`.

Replace `Bool` fields with `Coerced(bool)` to better support numpy bools.

The `web.core.db` module refactored and made into a package and split to
support both nosql and sql.

Application wrappers have been dropped. Just use `web.core.app.WebApplication`.

In order to handle websockets now, a `modified` event was added to the root
`Html` tag. This will be triggered with the change from every child node.
Simply have your websockets observe this event for changes and
handle it accordingly.