v0.16.0

This version tweaks the method which assign taxonomy to OTUs (increasing the species-level threshold) and the method which summarises the OTUs to create a final taxonomic profile (very low abundance lineages are given lower taxonomic resolution, rather than ignored completely. This improves the rate over "overclassification" i.e. when novel species are classified wrongly to the species level, and improves the read_fraction (now called microbial_fraction) estimates in complex / shallowly sequenced metagenomes.

We suggest recomputing community profiles using renew or pipe modes.

• pipe/renew: Change default species-level assignment from 3bp or closer, to 2bp or closer.
• pipe/renew/condense: Assign sub-min-taxon-coverage higher.
• read_fraction mode renamed to microbial_fraction

Thanks to Yu Yang, Caitlin Singleton, @MadsAlbertsen @EisenRa @BigDataBiology