Merge pull request #337 from shaitan/lts

Python: fixed writting out of memory.
trans: randomize route table update: select 5 random groups and read table from one random node from each selected group
Merge branch 'lts' of github.com:reverbrain/elliptics into lts
monitor: fixed monitor header ifdef decoration
v2.24.15.2
Python: added keeping node inside python elliptics.Session to insure that session will be deleted after node.
Merge branch 'lts' of github.com:reverbrain/elliptics into lts
Python: added ability to clone session.