Add @mraleph resources on microbenchmarks

[DavidBruant]

This is somewhat related to #137.
For inevitable reasons, benchmarks may be biased and may not measure what people expect. @mraleph made good explanations of this.
http://www.youtube.com/watch?v=65-RbBwZQdU
http://mrale.ph/blog/2012/12/15/microbenchmarks-fairy-tale.html
https://twitter.com/ubench_sphinx
Where would these links belong to? main page? FAQ?

[jdalton]

👍

[jdalton]

Maybe a disclaimer on the test page that links to an FAQ note or smth