marsadm: fix wait-cluster condition
marsadm: fix view/flags when network is slow
marsadm: fix sync check
marsadm: workaround concept bug in _get_actual_primary(), deprecate it

The conceptual bug was leading to systematic false-positive failures in the
old test_suite. These failures were depeding on the _names_ of the
involved hosts: just run it on a pair of differently named hosts
following different naming conventions, and 50 out of 90 testcases
were failing false-positively.
marsadm: fix incomplete syslog messaging
marsadm: fix usability of 'view'
light: fix becoming primary when logfiles are damaged

This adds /proc/sys/mars/allow_primary_when damaged
Prividing this is absolutely necessary.
Otherwise repair would be only possible by complete destruction
of the resource.
marsadm: fix forgotten unlinks in {invalidate,leave-resource}
marsadm: start 'primary' handover after fetch has completed
light: fix zero progress of rate display
marsadm: fix split brain prevention on handover
net: fix unnecessary socket shutdown on nonblocking connects
light: fix long-lasting pause-fetch effect
infra: move io_timeout to generic interface

This is needed for the next commit.
light: fix client shutdown on slow network

On slow networks, the generic net_io_timeout is too long if you are
impatiently waiting for disconnect.

Change the io_timeout of the individual client brick to a short value.
light: fix copy switch off
net: fix long-lasting disconnects, abort send/recv in realtime

Use realtime units (seconds) for aborting network operations.
This is important for some operations when the network has an
extreme bottleneck.