Remove qiime.parse.filter_otus_by_lineage

This function wasn't being used anywhere in QIIME. Noticed this while updating QIIME to use skbio's subsample functionality.
update alpha_diversity.py to use skbio's subsample
update qiime.rarefaction to use skbio's subsample
Merge branch 'master' into subsample

Conflicts:
	qiime/parse.py
	tests/test_rarefaction.py
Merge pull request #1461 from ElBrogrammer/subsample

Update to use skbio's subsample