Moderators are able to send a message to the meeting's guest lobby. This new
event reaches bbb-web and is sent to the guest user with her/his status response
while polling. All guest users that are waiting for acceptance will be able to
read this message.

enableGuestLobbyMessage is disabled by default.

Removes loginTime creation from Meteor and use the registeredOn date created on Akka. Makes Akka send the registeredOn date throught PubSub messages: UserRegisteredRespMsg, GuestsWaitingForApprovalEvtMsg and ValidateAuthTokenRespMsg.