Centralized webapp logging

[Luke Macken]

I setup Bodhi in staging to log to syslog instead of to stderr, which
ends up in /var/log/httpd/error_log.

The logs now appear in
/var/log/hosts/<HOST>/<YEAR>/<MONTH>/<DAY>/apps.log on log02, and in the
merged log /var/log/merged/apps.log.

In an effort to start building a "Best Practices for Infra Apps", I
threw a couple examples of how to do this on the wiki:

    https://fedoraproject.org/wiki/Infrastructure/AppBestPractices

I also opened a ticket to track our progress:

    https://fedorahosted.org/fedora-infrastructure/ticket/3627

luke