erasure-code: benchmarking jerasure

On a Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz processor (and all SIMD capable Intel processors) the Reed Solomon technique of the jerasure plugin, which is the default in Ceph Firefly, performs better. Introduce HTML display to facilitate benchmark intepretation.

![simd](https://cloud.githubusercontent.com/assets/433594/3096650/92401594-e5d6-11e3-9f9b-fc2fc37fb4ac.png)

Modify the alignment constraints to enable Cauchy technique on small objects (4KB).