This is a (hopefully) temporary fork of tmlong's Gmail Manager addon, to fix
obviously broken things that make it difficult for me to use.  I do not plan on
maintaining this long-term; expect it to be ignored and rot.  If you find any
problems, please use the fork button on the github page.

Hopefully he'll come back and update the addon again; in the mean time, since I
already need to fix it for myself, I might as well put the changes up under the
original tri-license (MPL 1.1/GPL 2.0/LGPL 2.1).