Added support for showing key fingerpints.

//BUG The first byte character doesn't match what the Textsecure android displays
Update README with wiki and mailing list links
Merge branch 'master' of https://github.com/janimo/textsecure into fingerprint
Go fmt cleanup
Support for a password of "none". Moxie has indicated support for relying on existing full disk encryption
Perliminary support for communicating with multiple users
Merge branch 'master' of https://github.com/janimo/textsecure
Merge branch 'fingerprint'