Arch package for version 0.7
Extract a TermInfo class.

So far, we've only used the `tput` command to determine if the terminal
supports colours. In order to fix the window size bugs, we'll also need to
use `tput` to get the size of the terminal emulator. Extracting a TermInfo
objects lets us do that without any repetition.
Make dependency explicit.
Don't wrap injected Readline object.

If the InteractiveRunner wraps whatever injected Readline object it's given
in a ReadlineBlankFilter, then we have to provide a bigger interface than we
would otherwise need.
Handle SIGWINCH, and tell Readline to resize.
Tidy up exception expectation.