Fix file access permissions and group ownership for Apache2 SSL

Fix file access permissions and group ownership for Apache2 SSL
certificate files, new file names for CA (carnet-generate-ssl).
Problems in debian/postrm - not removing all DocumentRoot
directories, $CONFDIR was not defined.
Script debian/postinst - check for both PHP5 and PHP4 modules.
Changed dependencies in debian/control.
Changes in debian/prerm script.
Added dh_installdebconf in debian/rules.