EX-3476 lipe-scripts: Add --now to hp stop

EX-3476 lipe-scripts: Add --now to hp stop

The --now option will, after stopping lamigo/lpurge, kill all lfs mirror commands
and unmount the clients.  This is to aid in a full filesystem shutdown.

Change-Id: I852383b9523068a75a047e5f640f2d28057e0c64
Signed-off-by: Nathaniel Clark <nclark@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/44304
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Gaurang Tapase <gtapase@ddn.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>