init-radosgw.sysv:  New radosgw init file for rpm based systems

Added init-radosgw.sys file for rpm based systems, added it to
the tarball list in the makefile, and updated the specfile to
install it.  Also added the a dependency in ceph since it uses
utility routes from that package (On debian systems these are
packaged in ceph-common).  Incorporated review comments from
Alex. (Bug #4571)

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>
Reviewed-by: Alexandre Marangone  <alexandre.marangone@inktank.com>