Generic benchmarks

[liran-funaro]

Generic benchmarks and:

• support event-cache key/values in benchmarks
• consume key/values
• quantile latency measurements
• Chronicle and Memcached implementations
• increasing put preserves cardinality
• parallel (faster) initialization
• insert pre-defined scenarios into Parameters.
• nicer parameters usage/print
• removes redundant (old) code
• fix memory leak in the benchmarks

I confirm that this contribution is made under the terms of the license found in the root directory of this repository's source tree and that I have the authority necessary to make this contribution on behalf of its copyright owner.

[sanastas]

My biggest concern now is that we need a design document together with this change. If myself or other committers will need to change something in the way benchmarks are done, it would be hard to do without some guidance.

[liran-funaro]

@sanastas

My biggest concern now is that we need a design document together with this change. If myself or other committers will need to change something in the way benchmarks are done, it would be hard to do without some guidance.

I can add a readme file to the synchrobench module. What would you like to be documented? Note that the benchmark class usage is documented. You just need to execute it with -h/--help flag.