Add initial write-through cache benchmark
WIP
tmp
Do not prune on each write operation of the mutable TTL cache
Optimize + refactor from real usage
Fix some missed updates
Remove final, for a var

And add a comment on the store
Remove commented code
Update the pr.

Make the CMS a proxy on a cache rather than a store.

Add a eager write through store thats simple + fast and will update the cache before we have a confirmed store write.

add a test for the Filtered Cache
Converge the get/put timers in the benchmark
Fixup not-renamed
Review comments. Do not eagerly evaluate clock(), don't need to reset atomic int
Merge pull request #234 from twitter/feature/writeThroughCachePerf

Feature/write through cache perf