I've noticed people have some problems getting me logs when there'a a bug,
so I worked on improving the logging of the assistant.

While the assistant logged to `.git/annex/daemon.log` when started as a
daemon, when the webapp ran it didn't log there. It's somewhat tricky to
make the webapp redirect messages to the log, because it may start a web
browser that wants to write to the console. Took some file descriptor
juggling, but I made this work. Now the log is even used when the assistant
is started for the first time in a newly created repository. So, we have
total log coverage.

Next, I made a simple page in the webapp to display the accumulated logs.
It does not currently refresh as new things are logged. But it's easier
for me to tell users to click on `Current Repository -> View log` than
ask for them to look for the daemon.log file.

Finally, I made all the webapp's alerts also be written to the log.

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Also did the requisite bug fixes.

[[!img /assistant/logs.png alt="screenshot of logs page"]]
