New wokflow

Here's the idea for the new recording/publishing workflow:

* `asciinema rec` - record the terminal session, it gets saved in your local "repository",
* `asciinema ls` - see what's local (not published),
* `asciinema ls -r` - see what's remote (published),
* `asciinema rm <id>` - delete it,
* `asciinema play <id>` - replay it in your terminal,
* `asciinema edit <id>` - fire up $EDITOR and edit title, description and the content itself (fixing typos!),
* `asciinema process <id> ...` - post-process the recording (optimizations like: removing idle time, speeding it up, etc. Also, running the recorded content through arbitrary command) 

See this gist for example workflow: https://gist.github.com/sickill/c83e9f972c89dd76ef95