>http://stackoverflow.com/questions/16335327/fasta-delete-sequences-after-n-length
abcdef
>bar
....5...10....5...20....5...30....5...40....5...50....5
...60....5...70....5...80....5...90....5..100....5...10
....5...20....5...30....5...40....5...50....5...60....5
...70....5...80....5...90....5..200....5...10....5...20
....5...30....5...40....5...50
>baz
abcdef