Changed error_t to storage_error_t
Additional comment for iterate_thread_num
Moved elliptics_timer to local_session.h
Added more timers to built-in cache
Added more timer logs to cache
Moved from std::chrono to dnet_time in timer logs
Fixed elliptics_timer sign
Additional fix of signs in elliptics_timer
Added elliptics_unique_lock for more log info
Fixed log verbosity for cache erasing
Fixed syncing of all syncable objects in cache at overflow
Changed atomic from int to long to fix overflow
Return -ENOTSUP if backend don't know the command
Merge pull request #238 from euroelessar/master

A lot of changes