Creates the room according to some default configuration, assign the requesting user as the room owner, and add the owner to the room but not allow anyone else to enter the room (effectively "locking" the room). The requesting user will join the room under the specified nickname as soon as the room has been created.
To create an "Instant Room", that means a room with some default configuration that is available for immediate access, the room's owner should send an empty form after creating the room. {@link #sendConfigurationForm(Form)}
To create a "Reserved Room", that means a room manually configured by the room creator before anyone is allowed to enter, the room's owner should complete and send a form after creating the room. Once the completed configutation form is sent to the server, the server will unlock the room. {@link #sendConfigurationForm(Form)}
@param nickname the nickname to use.
@throws XMPPException if the room couldn't be created for some reason(e.g. room already exists; user already joined to an existant room or 405 error if the user is not allowed to create the room)