ipaserver: remove ipalib import from setup.py
    
    Instead of importing ipalib to get IPA version string, create setup.py from
    a template and have the version string automatically filled in.
    
    This makes it possible to build the ipaserver package without having to
    have ipalib dependencies installed.
    
    https://fedorahosted.org/freeipa/ticket/6418
    
    Reviewed-By: Petr Spacek <pspacek@redhat.com>
    Reviewed-By: Martin Basti <mbasti@redhat.com>