sysklogd: convert to gentargets and bump to 1.5

Also, changed the site to Debian, to get the latest patches

[ Thomas: Minor fixes. Removed S25sysklogd since our default
  /etc/inittab already starts klogd and sysklogd. ]

[Peter: only install syslog.conf if not available in skeleton]
Signed-off-by: Martin Banky <Martin.Banky@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>