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.
Remove the __len__ functions, as they exhaust the iterator, breaking
'list(x)'.
This is a follow-up to 8866a89e.
Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de>
Cleanup the code, reword the docstring and use the same implementation
in the Threads, Tags and Messages classes.
__nonzero__ implements truth value testing. If __nonzero__ is not
implemented, the python runtime would fall back to `len(..) > 0` thus
exhausting the iterator.
Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de>
