Cryptocat 2.1.3

- New feature: Block users! Prevents annoying users from sending you
messages/from seeing your messages.
- New feature: Typing notification. See when a user is composing a
message (both users need to be using Cryptocat 2.1.3 or higher.)
- Fixed a bug that would prevent conversations from scrolling down when
tabs are switched.
- Fixed a bug that prevented nickname tab completion from working.
- Fixed a bug that would prevent some ZIP files from being transferred.
- Fixed a bug that would prevent audio and desktop notification
settings from being saved.
- Fixed a bug that would prevent a user from logging back in after
logging out.
- Fixed a bug that would show a vertical scroll bar on logout for no
reason.
- Additional small bug fixes.
- Uighur translation has returned.