Use binary version of perl mcrypt module instead of having build-essential in container

Dockerfile

@@ -15,31 +15,28 @@ RUN apt-get -y update && \
 	    mysql-server \
 	    php5-mysql \
 	    php5-mcrypt \
-	    libmcrypt-dev \
+	    libmcrypt4 \
 	    libwww-perl \
 	    libdigest-whirlpool-perl \
 	    pwgen \
 	    curl \
 	    openssl \
-	    cpanminus \
-	    build-essential \
-	    libltdl-dev \
     && \
     apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
-RUN cpanm Mcrypt
-
 RUN useradd -d /var/www/fic-server/misc/ -M -N -g www-data synchro
 
-WORKDIR /var/www/fic-server/misc
-
 # Copying files #######################################################
 
+WORKDIR /var/www/fic-server/misc
+
 ADD . /var/www/fic-server/
 
 # Configure softwares #################################################
 
-RUN ln -sf /var/www/fic-server/nginx-server.conf /etc/nginx/sites-enabled/default && \
+RUN dpkg -i /var/www/fic-server/libmcrypt-perl*.deb || \
+    (echo "Please build perl-mcrypt first. Consult the given README!"; exit 1) && \
+    ln -sf /var/www/fic-server/nginx-server.conf /etc/nginx/sites-enabled/default && \
     ln -sf /var/www/fic-server/php-fpm.conf /etc/php5/fpm/pool.d/www.conf
 
 # Generate test certificates ##########################################