Add the regex-dna benchmark about pyperformance

[vstinner]

Good news: performance 0.3.1 includes the new benchmarks. FYI it's called "fasta" in pyston benchmark suite.

[matrixise]

See http://bugs.python.org/issue26436 for details.

Proposed patch adds the regex-dna benchmark from The Computer Language Benchmarks Game (http://benchmarksgame.alioth.debian.org/). This is artificial but well known benchmark.

The patch is based on regex-dna Python 3 #5 program and fasta Python 3 #3 program (for generating input).

http://bugs.python.org/file42028/bm_regex_dna.patch

[vstinner]

I created the pull request #17 with Serhiy's patch (updated for latest perf and performance).