php7/php7-pecl-*: introduce load order

php7/php7-pecl-*: introduce load order

Some PECL modules (possibly also php modules) depend on
special load order, otherwise loading the module will fail
due to unresolvable symbols.

This changeset introduces a very simple compile-time defined
order by specifying a prefix for the ini file with the load
directive. If not given, it uses a default value.

It also updates all current pecl module packages to take
this new approach.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>