Add test for write_seqs_to_fastq
Change test to reflect new api

split_fasta_on_sample_ids_to_files got a few new arguments
Change write_seqs_to_fasta; use context manager
Add write_seqs_to_fastq function
Change name of function
Change name of function in tests
Add option for FASTQ files, usage example
Use new function API where needed throughout QIIME
Rename qiime_test_data dir and add fastq file
Add mention of changes to ChangeLog.md
Merge pull request #1675 from adamrp/split_fastq

Add FASTQ splitting by sample id to qiime.util