Import of docker-php-ext-* scripts from PHP Docker image

These scripts allow to deploy a new installation when the image is
running. This could be used in Dockerfile of app using our base web
server image, or live in further deployment processes.

• Source: https://github.com/docker-library/php/tree/master/5.6/fpm
• Revision at import time: 58c3fd175cb3ab30633fbc3e86314154ecc38e89
• License: MIT