plugin XEP-0313: cleaning and improvments: - moved common namespaces to core.constants - removed useless dependencies and recommendations - removed all bride methods as they where there only for testing purpose - don't use a plugin dict to store MAM clients, put them in profiles' clients instead - removed message trigger in favor of an observer which is triggered only when specific queryid is used - new getArchives method which grab all result and return them all at once

Use this module to temporary store files that need to be integrated to other
projects such as Wokkel.

For example, the changeset that introduced this folder adds RSM (XEP-0059)
support to Wokkel. The files in sat.tmp.wokkel are imported over the initial
wokkel files from sat.plugins.__init__.py