support for CentOS 5.x, plus version name and buildreq fix

Build was creating haproxy-1.5.0-1.5.0.x86_64.rpm instead of haproxy-1.5.0-1.x86_64.rpm.  Pegging to setup 2.8 was not needed, repegged to 2.5.  Setup is a buildreq, not req.