[autobuild] use autoreconf instead of calling tools manually

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/spawn-fcgi/trunk@61 4a9f3682-ca7b-49a8-9a55-ba4640e46f83
Add more flags to extra-warnings flags

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/spawn-fcgi/trunk@62 4a9f3682-ca7b-49a8-9a55-ba4640e46f83
Check return values of setuid, setgid, setgroups, initgroups, write

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/spawn-fcgi/trunk@63 4a9f3682-ca7b-49a8-9a55-ba4640e46f83
Add packdist.sh to build tar balls; but not part of the tarball itself.

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/spawn-fcgi/trunk@64 4a9f3682-ca7b-49a8-9a55-ba4640e46f83