Move log callback to options.

Previously, all log messages generated by tox_new (which is quite a lot)
were dropped, because client code had no chance to register a logging
callback, yet. This change allows setting the log callback from the
beginning and removes the ability to unset it.

Since the log callback is forever special, since it can't be stateless,
we don't necessarily need to treat it uniformly (with `event`).

0 files changed, 0 insertions, 0 deletions