Don't use extension.ini any more, and have each extension install in its
file, so the order remains the same.

Every PHP (or Zend) extension now installs its own .ini file in
/usr/local/etc/php. A PHP extension will be automatically activated
when installed. The order into which extensions are loaded is
automatically guessed. In some very rare cases, the guess will be
wrong, and PHP_MOD_PRIO will need to be set. Refer to the USES=php
section of the Porter's Handbook for more information.

Convert ports touching etc/php/extensions.ini manually, or telling the
OP to do it.

And finally, bump PORTREVISION for all php extensions.

PR: 210697
Submitted by: mat
Sponsored by: Absolight
Differential Revision: https://reviews.freebsd.org/D7022