Document glob bugs

Until we can get a handle on globbing, we cannot close #11. That bug is
the last remaining ticket blocking the 1.2.1 release. However, it may
involve a larger modification than a patch release should. Documenting
allows us to make the release while working on the bug for the next
release.

http://1389blog.com/pix/thats-a-feature-not-a-bug.jpg