CP-4666: Make suspend without tools dependent on a server-side flag

Signed-off-by: Vincent Bernardoff <vincent.bernardoff@citrix.com>
CP-4666: Import the refactoring code made for CP-4666 without the server-side flag

Signed-off-by: Vincent Bernardoff <vincent.bernardoff@citrix.com>
Merge pull request #1209 from vbmithr/master

CP-4666 improvements to xapi_vm_lifecycle.ml