Update from 1.15.0 to 1.16.0.

Sort knobs, configure arguments, and sub list.

This release improves the functionality related to
proxying and static media asset handling, please visit
http://mailman.nginx.org/pipermail/unit/2020-March/000195.html
to get more details.

<ChangeLog>

*) Feature: basic load-balancing support with round-robin.

*) Feature: a "fallback" option that performs an alternative action if a

request can't be served from the "share" directory.

*) Feature: reduced memory consumption by dumping large request bodies

to disk.

*) Feature: stripping UTF-8 BOM and JavaScript-style comments from

uploaded JSON.

*) Bugfix: negative address matching in router might work improperly in

combination with non-negative patterns.

*) Bugfix: Java Spring applications failed to run; the bug had appeared

in 1.10.0.

*) Bugfix: PHP 7.4 was broken if it was built with thread safety

enabled.

*) Bugfix: compatibility issues with some Python applications.

</ChangeLog>