Cache: Copyright added, time_stats added
Merge branch 'master' of https://github.com/reverbrain/elliptics into io_stats
Cache: time_stats, json, erase_strategy

- time_stats tree refactored
- cache stats conversion to json added
- cache overflow erase strategy changed to avoid writes or reads on
  keys to be synced.
Pytests: Created draft of python binding automated testing.
The draft includes:
Testing default, limits and valid values of elliptics.Config properties.
Testing default, limits and valid values of elliptics.Session properties.
Simple test case for writing object.
CMake workaround for preparing and running pytests.
Cache: timestats refactored
Merge branch 'master' of https://github.com/reverbrain/elliptics into io_stats

Conflicts:
	cache/cache.cpp
	monitor/statistics.cpp

Cache: merge with master
Cache: timers replaced with time_stats
Cache: compilation on gcc4.4 fixed
Cache: Bug with erase in lifecheck fixed
Cache: memory corruption fixed
Cache: Copy of data before sync added
Cache: bug with double erase fixed
Cache: deadlock fixed
Merge branch 'master' of https://github.com/reverbrain/elliptics into io_stats
Cache: monitoring max_depth added
Cache: time_stats doxygen documentation added
Added forgotten doc/Doxy*.in files
Cache: time_stats docs prettified
Cache: Monitoring example added
Cache: Actions set added.