The '--offload' option allows us to explicitly request that the server
be offloaded once shelved or if already shelved.
The '--wait' option allows us to wait for the shelve and/or offload
operations to complete before returning. It is implied when attempting
to offload a server than is not yet shelved.
Change-Id: Id226831e3c09bc95c34b222151b27391a844b073
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>