Details here: https://prosody.im/issues/1121

- for subscription requests
- when entering chat rooms

Otherwise the contact stays visible under "Pending Contacts" although
the subscription request has been accepted.

when it's created due to a new contact being added.

Was previously in the wrong place.

by calling `sortAndPositionAllItems`.

Particularly relevant to the "Pending Contacts" group.

to make it clearer that this toggle relates to chatting.

to avoid name clashes

because it didn't actually clear anything permanently and upon page
reload the messages were there again.

This cause the error "Mismatched anonymous define" when loading the
bundle in Plone.

The original reason for adding `start.frag` was to wrap the bundle in a
closure to not pollute the global namespace (e.g. overriding global
`define` and `require` with Almond`s versions) and secondarily to allow
people to load the bundle via require.js.

The second usecase should now probably be done via a shim in the
require.js config.