Clean up build requires lines
    
    Drop podlators since QEMU no longer uses POD for man pages.
    
    Drop all version numbers, since we can assume Fedora has new enough
    packages.
    
    Make comments a little more consistent.
    
    Drop rados2-devel  as it is implied by rbd-devel
    
    Use rbd-devel instead of rbd1-devel due to rename
    
    Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>