syweb's default install assumes that:
  - apache is chrooted at /var/www
  - rrdtool is installed in the chroot
  - symux rrd files are kept in /var/www/symon/rrds/<host>/*.rrd

rrdtool can be installed in the chroot using
  /var/www/symon/install_rrdtool.sh

Customise /var/www/htdocs/syweb/setup.inc if these assumptions are
incorrect.
