added note on usearch61
Merge pull request #960 from gregcaporaso/updated-script-docs

updated automated script documentation
Merge pull request #961 from gregcaporaso/issue-959

added note on usearch61
updated for 1.7.0

Fixes #957.
Merge pull request #962 from gregcaporaso/issue-957

updated for 1.7.0
Changed __version__: 1.6.0-dev to 1.7.0
Changed __status__: "Development" to "Release"
Updated doc/conf.py version
Updated version strings in docs.
Fixed some RST script errors.
Fixed otu_cat_sig.py output desc to avoid errors
Merge pull request #964 from jrrideout/170-version-change

Version updates for 1.7.0.
fixed issue where %prog was not replaced with script name