-- Related: #8664

In PGPy 0.4.0 keys are not accepted if they have empty lines before the
ascii armored text. I addapt the tests around that for now. This is fixed
already in PGPy repo, so it will not be an issue in comming releases.

- Resolves: #8558, #8663

For expired keys gnupg will not allow us to encrypt (to force it we'll
need to fake the system date). Let's bounce the email properly in this case,
and register the error.

Make sure as well that _encrypt_message does not return None, let's
raise exceptions in case of failure.

- Related: #8663

Leap MX was previously wrapping soledad's couchdb-related exceptions
messages in its own exception. The problem was that message attribute of
those exceptions were actually empty, and so the information of the
actual error was lost. This commit removes the wrapper exception and
forwards whatever exception was received from soledad to the logging
system.

Signed-off-by: Ruben Pollan <meskio@sindominio.net>

Do not reconstruct the message from the parsed one. Added test for
missleading encoding.

- Resolves: #7253

- Resolves: #5959

Some refactor on the couchdb usage was needed to be able to mock
couchdb.

- Resolves: #7435

- Resolves: #7439