1.9.13 `distance` adds "wunifrac" option.

Merge branch 'pr/384'
CHANGES IN VERSION 1.9.13
-------------------------

USER-VISIBLE CHANGES

	- `distance` function now supports "wunifrac" option, for
`UniFrac(..., weighted=TRUE)`

	- `distance` function regexpr-matching for range of variants for
weighted-UniFrac, unweighted-UniFrac method option

	- `distance` function regexpr-matching for `type` argument range of
alternatives

	- Proposed in https://github.com/joey711/phyloseq/pull/384
1.9.14 distance/DPCoA bug fix. Update contact info

CHANGES IN VERSION 1.9.14
-------------------------

BUG FIXES

	- `distance` erroneously transformed Rao distance results for method
DPCoA. Now Fixed.

	- Originally posted, described at
https://github.com/joey711/phyloseq/issues/390
1.9.15 remove pseudocount addition in phyloseq_to_deseq2

CHANGES IN VERSION 1.9.15
-------------------------

BUG FIXES

	- `phyloseq_to_deseq2` was adding an unnecessary pseudocount of `1` to
the count matrix. No longer.

	- Originally described at
https://github.com/joey711/phyloseq/issues/387
1.9.15 remove pseudocount addition in phyloseq_to_deseq2

Fix a help documentation error that arises without pseudocount
https://github.com/joey711/phyloseq/issues/387