Many of the external links found in the notmuch source can be resolved
using https instead of http. This changeset addresses as many as i
could find, without touching the e-mail corpus or expected outputs
found in tests.
Add various functions to print notmuch messages and tie them together
with a simple frontend.
Add a binding ('#') in `notmuch-show-mode' to print the current
message.
one trailing space removed by db.
