DOC/STY: cleaned up text and made a couple of minor code changes
Merge pull request #715 from gregcaporaso/issue-708

review of fasta docs
Merge branch 'master' into issue-681
Add invalid FASTQ example files taken from open-access publication

Example files taken from:

P.J.A. Cock, C.J. Fields, N. Goto, M.L. Heuer and P.M. Rice (2009). The
Sanger FASTQ file format for sequences with quality scores, and the
Solexa/Illumina FASTQ variants.

See licenses/fastq-example-files-readme.txt for the terms of use.