Cache: time statistics added
Cache: fixed constructor for gcc4.4
Cache: typo fixed
Elliptics timer upgraded
Cache: fixed append cache size recalc
Cache: Bug fixes, tests added

Bug with page size recalc fixed.
Test for checking overflow behaviour added.
Function to clear cache added.
Cache: pages space reservation added
Cache: Stats per cache added
Cache: treap merge and insert optimized
Cache: treap priority comparator changed
Cache: stats added, life_check strategy changed

Additional cache time stats added.
life_check now holds lock for all events.
Cache: life_check sync strategy changed
Cache: code style in treap fixed
Merge branch 'master' of https://github.com/reverbrain/elliptics into cache_treap

Conflicts:
	cache/slru_cache.cpp

Cache: stats merged
Cache: duplicate stats removed
Merge branch 'master' of https://github.com/reverbrain/elliptics into cache_treap
Merge pull request #306 from IIoTeP9HuY/cache_treap

Cache stats and optimization