WIP: reduce number of mails per day, from 3 down to 2, see #912591.

master-bin/generate_daily_report:
- redirect logs of called scripts to htdocs/logs.
- include listing of htdocs/logs/$TODAY into daily report.
- publish dailyreport.txt in htdocs/logs/$TODAY instead of htdocs/.

Signed-off-by: Holger Levsen <holger@layer-acht.org>