Pytests: fixed vfs statistics test - zero value for some metrics is valid.
Recovery: fixed circular references in dc recovery. Fixed static analysis and memory profiler warnings.
Merge pull request #534 from shaitan/master

Pytests and dnet_recovery fixes
monitor: clear dnet_vm_stat at dnet_get_vm_stat.
trans: when destructing transaction, write not only state, but also backend
file: fixed file_info timestamp reading
monitor: added 'error' and 'string_error' to procfs statistics: vm, io and proc.
Pytests: if procfs statistics: vm, io or stat; contain nonzero error - do not asserts internal statistics.
Merge pull request #535 from shaitan/master

Fixed garbage at unitialized vm statistics if procfs and sysctl are not available.
recovery: fixed multiple open at one with (python2.6).
Merge pull request #536 from shaitan/master

recovery: fixed multiple open at one with (python2.6)
recovery: added another one (last) fix for compatibility with python2.6 which doesn't support multiple open with one with
Merge pull request #537 from shaitan/master

recovery: added another one (last) fix for compatibility with python2.6 ...
Merge branch 'master' of github.com:reverbrain/elliptics
v2.26.3.27
Merge branch 'master' of https://github.com/reverbrain/elliptics into passthrought_original_id