[qmf] Introduce discovery of authentication from the anounced capabilities(IMAP/SMTP)
[qmf] Handle SMTP response 504.

Handle SMTP response 504 and reset auth method if auth from caps is
enabled.
Merge pull request #63 from nemomobile-packages/smtpAuth

[qmf] Introduce discovery of authentication from the anounced capabilities(IMAP/SMTP)