register, login, some search function

changes:
* register.
* login;
* search jids by cellphone number;
* search jid, nickname, photo by cellphone number or email.
*write cellphone number or email into vcard, vcard_search when register.
`cellphone` -> `tel` according to [XEP-0054: vcard-temp](http://xmpp.org/extensions/xep-0054.html)