light: remove superfluous timeout parameter

The concept was broken.
infra: disallow forbidden brick states

Switch on only when all predecessor bricks are also on.
Failing to do so can result in fatal errors.
Similarly, switch only off if no successor exists any more.
infra: don't switch off if predecessors are working
infra: remove recursive button operations

All buttons should be switched step-by-step in future.
The previous patch should ensure that no harm can occur.
infra: remove superfluous parameter is_server
infra: replace brick_version by kill_round
light: fix detach operation
light: fix logfile replication when trans_logger is not running
infra: systematics of make_brick_all() switching, remove superfluos parameter
aio: avoid cluttering the log messages
marsadm: add new command 'wait-umount'
marsadm: add new command 'wait-cluster'