Update from 1.18.0 to 1.19.0.

<ChangeLog>

*) Feature: reworked IPC between the router process and the applications

to lower latencies, increase performance, and improve scalability.

*) Feature: support for an arbitrary number of wildcards in route

matching patterns.

*) Feature: chunked transfer encoding in proxy responses.

*) Feature: basic variables support in the "pass" option.

*) Feature: compatibility with PHP 8 Beta 1. Thanks to Remi Collet.

*) Bugfix: the router process could crash while passing requests to an

application under high load.

*) Bugfix: a number of language modules failed to build on some systems;

the bug had appeared in 1.18.0.

*) Bugfix: time in error log messages from PHP applications could lag.

*) Bugfix: reconfiguration requests could hang if an application had

failed to start; the bug had appeared in 1.18.0.

*) Bugfix: memory leak during reconfiguration.

*) Bugfix: the daemon didn't start without language modules; the bug had

appeared in 1.18.0.

*) Bugfix: the router process could crash at exit.

*) Bugfix: Node.js applications could crash at exit.

*) Bugfix: the Ruby module could be linked against a wrong library

version.

</ChangeLog>