[CRIU] [PATCH 0/5] Task credentials support

[Pavel Emelyanov]

This set mess with task IDs (user, group, effective, etc.), capabilities
and securebits.

TODO:
 * Fix threaded case -- see comment in restorer.c about this
 * Support groups -- the xgid set is not the only one used in kernel
 * Implement API for spawning tasks in zdtm -- all the tests for this
   functionality use homebrew one since it's not always possible to 
   write .pid or .out files after changing ID-s or CAP-s :(

Signed-off-by: Pavel Emelyanov <xemul at parallels.com>