Better filtering for /etc/cron.daily/chkrootkit (Closes #630880)
Per the message to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=630880 this change
- improves the filtering for /etc/cron.daily/chkrootkit by expanding the list of 'allowed' packet sniffers to include wpa_supplicant, dhcpcd, etc
- quotes more variables
- makes tabs consistent
- includes stderr in the output (just in case)