Improve job submission log and event hook log locations

[matthewrmshin]

Submission error output, currently goes to log/suite/err, can be lost in the noise.
Users are often puzzled when they have a submission failure. Ditto event hook logs.

Should we send job submission and event hook logs to live with the other job logs?

See also #991 and #994.

[hjoliver]

Should we send job submission and event hook logs to live with the other job logs?

The suite daemon submits jobs, so it makes perfect sense for stderr from job submission commands to appear in suite daemon stderr. If you llsubmit job.sh at the command line, should you expect stderr from the llsubmit command to end up in or with the job execution logs?! However, some (perhaps most?) users do unfortunately seem to struggle with this concept. The trouble with moving the error output is that instead of confusing them, we might instead confuse the (morally superior!) users who actually made the effort to think about and understand how jobs get submitted). So I guess we need the output in both places.

[hjoliver]

Oops, I just rediscovered this issue, which I thought we'd only discussed by email, hence my hostile takeover in #1112 (followed up by @matthewrmshin in #1118. Anyhow, this is now done.