Add --without-ipatests option
    
    --without-ipatests skips building and installation of the ipatests
    package. By default the ipatests package is always build and installed
    by make install.
    
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Simo Sorce <ssorce@redhat.com>
    Reviewed-By: Tomas Krizek <tkrizek@redhat.com>