[CRIU] [PATCH 0/7] tty, c/r for ext connections

[Cyrill Gorcunov]

Hi guys, here is an updated variant of external tty migration.
Note there is some work to be done on top -- the restore of sids
if -d option passed and we're dumping only a subtree of some
process tree.

But if there is no principal objections I would like to merge
this series if possible and do further work on top.

(Once I've rebased this series on top of current master
 I experience the followig error in ns tests

./unlink_fstat03 --pidfile=unlink_fstat03.pid --outfile=unlink_fstat03.out
--filename=unlink_fstat03.test

which were not there earlier even with this series applied)