Also filter 127 when printing to the terminal
Make fingerprint mismatches more prominent.

When starting an OTR session with a contact for whom one has fingerprint
saved, the message displayed when the resulting fingerprint is unknown
should be stronger than the case when no fingerprint is saved.
Add options to always encrypt conversations.

In order to prevent leakage, this change adds two config options:
AlwaysEncrypt and AlwaysEncryptWith. The former is a boolean that
controls whether unencrypted messages will ever be sent. The latter is a
list of Jabber uids to whom no unencrypted messages will ever be sent.