Benchmark with memory allocations

Hi all,
I've made a version of `benchmark-ips` that also shows memory allocations: https://github.com/jondot/benchmark-ipsa

It extends `benchmark-ips` by hijacking the `job` object and getting the call list. It does not have any performance implication over the original test session.

This is one step closer to the `go bench` tool which allows you to embed allocation info in addition to the iterations stats.