[MERGE] Improving check in myriad ways

[Daniel Mark Watkins]

Attached is a bundle which is the beginnings of work intended to fix LP
bugs 64783[0] and 96239[1].

This consists solely of the work I'd done in November, before RL got in
the way of my hacking.  I submitted it then and got some helpful
feedback, but have managed to lose that feedback, leaving me unsure as
to where to advance.

Any notes would be appreciated. :)


Dan

[Footnote 0: https://bugs.launchpad.net/bzr/+bug/64783]
[Footnote 1: https://bugs.launchpad.net/bzr/+bug/96239]