Add count_unique_sequences_per_otu and tests
Add write_contaminant_fasta and tests
Address comments from @wasade
Merge pull request #76 from adamrp/result_utils

Add count_unique_sequences_per_otu and tests
Merge branch 'master' of github.com:qiime/American-Gut into more_centralizing

Conflicts:
	americangut/results_utils.py