Update Tibetan translation (#331)
Cryptocat 2.1.13 (Pending public release)

- Group chat in this version of Cryptocat is not compatible with
previous versions. In order to be able to use group chat, all
participants must update to Cryptocat 2.1.13 or higher. Due to this,
this release will be delayed until it can be rolled out simultaneously
across all platforms. Updating is highly recommended.
- Important change: the "Block" feature has been changed to an "Ignore"
feature. You may ignore messages from users, but you can no longer
prevent them from receiving your messages. Ignored users will have a
strikethrough through their nickname, displayed in the buddy list.
- New feature: SMP authentication. You can now authenticate a buddy's
identity by asking them a secret question.
- New feature: Message previews! Private messages for conversations not
in focus are now previewed via small speech bubbles that appear next to
the buddy list.
- New feature: Cryptocat for Chrome, Firefox and Safari now displays
new message notifications inside the favicon, in the browser tab.
- Fixed an issue where users may be able to send group chat messages to
certain participants, but not to others.
- Fixed a bug where Cryptocat would not allow the file transfer of
certain types of ZIP files.
- Fixed an issue where Cryptocat would display private messages if they
were received without encryption. Now, all unencrypted messages are
dropped.
- Cryptocat's user interface has been improved in numerous areas.
- Add warnings for decryption failures and for situations where
Cryptocat thinks a user in the conversation is sending
cryptographically suspicious messages.
- Fixed a bug that would prevent buddy submenus from working if more
than one was open at the same time.
- Some work was done to resolve some potential openings for
cryptographic timing attacks.
- Fixed a bug that would prevent disconnection and logout messages from
displaying properly to the user disconnecting or logging out.
- Fixed a bug in Cryptocat for Firefox that would cause Cryptocat to
freeze for around one second when switching tabs.
- User join and part notifications and messages now include timestamps.

- Fixed a bug in Cryptocat for Mac that would add an unnecessary scroll
bar to the application window.
- Fixed a bug that would prevent more than two cat facts from being
displayed in one session.
- Cryptocat for Mac now bounces the dock when new messages are
received.
- Many translation mistakes and typos have been fixed.
- Many other small improvements and bug fixes.