feat(console): Name async command buffers.

[Droogans]

No description provided.

[Droogans]

I have a setup where I create a development.notes file in the root directory of projects, and put lots of common shell tasks inside of it. They get named stuff like "* console at ~/code/rb/project/", and so I end up manually renaming them to guard, rspec, selenium, etc.

This pull request automatically takes the first word of the command, and uses that as the buffer name.