Add new Strophe.Connection option `explicitResourceBinding`
Add new Strophe.Connection option `explicitResourceBinding`

If `explicitResourceBinding` is set to a truthy value, then the XMPP client
needs to explicitly call `Strophe.Connection.prototype.bind` once the XMPP
server has advertised the "urn:ietf:params:xml:ns:xmpp-bind" feature.

Making this step explicit allows client authors to first finish other
stream related tasks, such as setting up an XEP-0198 Stream Management
session, before binding the JID resource for this session.

strophe/strophejs,strophe/strophejs,strophe/strophejs