A new method which not only has Promise interface,
but also allows to queue IQs regardless of the current
connection's status.

Ping and send ICE failed notification requests are changed
to use this method which makes it more reliable on XMPP
Websocket connections on mobile(which in contrary to BOSH
dies much faster there).

The 'searchParams' are not implemented on react-native.

Copy/paste mistake - there's no such thing as this.connection in
the XmppConnection. Hard to track down because no error is logged.

Either connect or attach can be used to initiate the connection.

Use the rest argument expression to not miss any.

When Jiconop is used to attach to a warmed up BOSH session Strophe goes
to ATTACHED instead of the CONNECTED state.

The LastSuccessTracker has direct access to the Strophe.Connection.

The XMPP stream resumption will enable automatically if supported by
Prosody on Websocket connections. Pass the 'enableWebsocketResume'
config option set to 'false' to disable.

Websocket keep alive is HTTP GET request sent on the service URL passed
to Strophe. It is used to keep the stick tables alive. The feature comes
in enabled by default whenever Websocket are used. Pass
'websocketKeepAlive' config option set to -1 to disable.

See the code for more details about the default interval value.

The connected flag is flipped to true as soon as transport connection is
established by Strophe(such as WebSocket TCP), but it doesn't mean that
the connection is ready to send stanzas yet.

All calls to connection.send should go through the wrapper in order to
prevent breaking the connection by calling it in the not connected
state.

This prevents from accessing Strophe internals directly and allows to
block 'send' calls while disconnected. The latter breaks the stream
resume logic by putting stanzas onto the send queue.

TODO make jitsi strophe plugins use the XmppConnection wrapper whenever
possible instead of interacting with the Strophe.Connection directly.