added Token Based Reconnection and tested everything

[andresinaka]

@chrisballinger I implemented Token Based Reconnection. DON'T MERGE YET

Here is the documentation:
http://mongooseim.readthedocs.io/en/latest/open-extensions/token-reconnection/
http://www.xmpp.org/extensions/inbox/token-reconnection.html

There is something I can't find a way of implementing it, maybe you can give a clue:

When authenticating using TBR you send:

<auth xmlns="urn:ietf:params:xml:ns:xmpp-sasl" mechanism="X-OAUTH">here_goes_the_token</auth>

There are two types of tokens, the Access token that never changes and the Refresh Token that is refreshed every time you send it to the server, so after sending the <auth> with a Refresh Token the server will respond the following:

<success xmlns="urn:ietf:params:xml:ns:xmpp-sasl">new_refresh_token</success>   

And I need a way of being able to get that new_refresh_token. The different ways I found of doing this are:

• Make the id <XMPPSASLAuthentication> auth; from XMPPStream public (just the getter) and store the new_refresh_token in the auth (XMPPTBRAuthentication) so I can do somethign like this in the xmppStreamDidAuthenticate:

func xmppStreamDidAuthenticate(sender: XMPPStream!) {       
    print(sender.auth.refreshToken)
}

• Add a new delegate to XMPPStream.h something like:

- (void)xmppStreamDidRefreshTBRToken:(NSSTring *)token;

And call that method from - (void)handleAuth:(NSXMLElement *)authResponse in XMPPStream.m checking if auth is from type XMPPTBRAuthentication and grab the new_refresh_token from the authResponse

What do you think???