Implement support for multiple PHP versions

This commit provides docker images and scripts to support multiple
Debian and PHP releases via containers.

jessie_php5/Dockerfile-base

@@ -0,0 +1,38 @@
+FROM debian:jessie
+LABEL maintainer="jan@dittberner.info"
+VOLUME /srv
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive \
+    apt-get install -y --no-install-recommends \
+    ca-certificates \
+    curl \
+    libnss-ldap \
+    nullmailer \
+    php-apc \
+    php-mail \
+    php-mail-mime \
+    php-mail-mimedecode \
+    php-net-smtp \
+    php-net-socket \
+    php5-apcu \
+    php5-curl \
+    php5-fpm \
+    php5-gd \
+    php5-imagick \
+    php5-imap \
+    php5-json \
+    php5-mcrypt \
+    php5-pspell \
+    php5-sqlite \
+    psmisc \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*.*
+
+RUN curl -o dumb-init_1.2.2.deb -L https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_amd64.deb && \
+    dpkg -i dumb-init_1.2.2.deb && \
+    rm -f dumb-init_1.2.2.deb
+
+ADD --chown=root:root nsswitch.conf libnss-ldap.conf /etc/
+
+RUN rm -f /etc/php5/fpm/pool.d/www.conf