Merge pull request #217 from shaitan/trace

Added ability to trace request in logs both on client and on server sides.
v2.24.14.4
Revert "Merge pull request #217 from shaitan/trace"

This reverts commit 47c328c2bbeee65350ffca5e1a62c0348ad045cf, reversing
changes made to 5f0d34a28f7e66666770a46e1aa6f2927ed22e7b.
Put/complete stalled/timedout transactions on error not under state_lock.
Get rid of libelliptics_module_backend_cpp.so in elliptics spec
v2.24.14.5
We have to use list_for_each_entry_safe() when moving object from list being iterated.
v2.24.14.6
Do not reset state in auth/reverse lookup commands
v2.24.14.7
Fixed incorrect state used in timed out transactions cleanup
Returned back state reset in auth/reverse lookup
v2.24.14.8
Moved stall transaction processing into dnet_io_process(), where it can be done without races.
v2.24.14.9
Merge branch 'master' of github.com:reverbrain/elliptics into trace

Conflicts:
	bindings/cpp/callback_p.h
	bindings/cpp/log.cpp
	bindings/cpp/session.cpp
	bindings/cpp/session_indexes.hpp
	bindings/python/elliptics_python.cpp
	cache/cache.cpp
	example/common.c
	example/config.c
	example/find.cpp
	example/ioclient.cpp
	include/elliptics/backends.h
	include/elliptics/interface.h
	include/elliptics/session.hpp
	indexes/indexes.cpp
	indexes/local_session.cpp
	library/discovery.c
	library/dnet.c
	library/elliptics.h
	library/node.c
	library/notify.c
	library/pool.c
	library/trans.c