Prepare Onion Circuits 0.8.2 release

See merge request !9

Let's not log this by default (we log warning and higher), it's super common and
not a problem.

The Debian package already depends on it and I don't really see the value of
making this optional, so let's simplify the code.

This avoids loading code from CWD, ~/.local/lib/, etc.

Avoid crash when closing a already closed circuit

Closes tails#20003

See merge request !8

FWIW it actually doesn't break anything.

Remove deprecated functions

See merge request !7

Replicate Vidalia's ability to close arbitrary circuits

See merge request !6

Allow copying relay information

See merge request !5

Make setuptools aware no packages/modules are shipped

See merge request tails/onioncircuits!4