Release changes for 2.2.0

[jdeathe]

• Updates source image to 2.6.0.
• Updates php-hello-world to 0.12.0.
• Updates description in centos-ssh-apache-php-fcgi.register@.service.
• Updates Apache configuration to use DSO Module identifiers for consistency.
• Updates CHANGELOG.md to simplify maintenance.
• Updates README.md to simplify contents and improve readability.
• Updates README-short.txt to apply to all image variants.
• Updates Dockerfile org.deathe.description metadata LABEL for consistency + include PHP redis module.
• Updates wrapper to set httpd ErrorLog to /dev/stderr instead of /dev/stdout.
• Updates supervisord configuration to send error log output to stderr.
• Updates bootstrap timer to use UTC date timestamps.
• Updates bootstrap supervisord configuration file/priority to 20-httpd-bootstrap.conf/20.
• Updates httpd wrapper supervisord configuration file/priority to 70-httpd-wrapper.conf/70.
• Fixes bootstrap; ensure user creation occurs before setting ownership with user.
• Fixes docker host connection status check in Makefile.
• Adds PACKAGE_PATH placeholder/variable replacement in bootstrap of configuration files.
• Adds inspect, reload and top Makefile targets.
• Adds improved clean Makefile target; includes exited containers and dangling images.
• Adds SYSTEM_TIMEZONE handling to Makefile, scmi, systemd unit and docker-compose templates.
• Adds system time zone validation to healthcheck.
• Adds lock/state file to bootstrap/wrapper scripts.
• Adds php-wrapper and fcgid.conf as part of the service; removing dependency on the php-hello-world app.
• Removes unused DOCKER_PORT_MAP_TCP_22 variable from environment includes.
• Removes support for long image tags (i.e. centos-7-2.x.x).
• Removes APACHE_AUTOSTART_HTTPD_BOOTSTRAP, replaced with ENABLE_HTTPD_BOOTSTRAP.
• Removes APACHE_AUTOSTART_HTTPD_WRAPPER, replaced with ENABLE_HTTPD_WRAPPER.