Remove extra newlines from logging

Created by: jmdh

Some log processing tools don't handle empty lines well, so remove them. This also improves readability, attaching timestamps to content more closely.

Note that the core logging functionality also introduces additional newlines, which should arguably be removed as well. I've applied the trivial patch to my local installation to fix this there, but I need to look more carefully at callers to see what the impact is. Meanwhile this patch should be harmless.