Fix issue #11223335: APR: Lots of failures in procstats due to...

...bad cleanup of crashing processes

We now have a special path for crashing processes, to silently
clean up their state.

Also some tweaks to Log/Slog.wtf to get better stack crawl
summaries in APR.

Change-Id: Ieced26989907a6e7615b6fa033813fced78d7474