restructure dockerfile for later baseimage, also sab repo now pulling 0.8

Dockerfile

@@ -1,6 +1,11 @@
 FROM linuxserver/baseimage
 MAINTAINER Mark Burford <sparklyballs@gmail.com>
 
+ENV APTLIST="sabnzbdplus \
+sabnzbdplus-theme-mobile \
+unrar \
+wget"
+
 # Set the locale
 ENV LANG=en_US.UTF-8 LANGUAGE=en_US:en LC_ALL=en_US.UTF-8
 RUN locale-gen en_US.UTF-8
@@ -12,27 +17,23 @@ apt-get install libtbb2 -qy && \
 dpkg -i /tmp/par2-tbb_*.deb && \
 rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
-# install main packages
+# install main packages
 RUN add-apt-repository ppa:jcfp/ppa && \
 apt-get update -q && \
 apt-get install \
-curl \
-sabnzbdplus \ 
-sabnzbdplus-theme-mobile \ 
-unrar \
-wget -qy && \
+$APTLIST -qy && \
 apt-get clean -y && \
 rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
+# adding custom files
+ADD services/ /etc/service/
+ADD init/ /etc/my_init.d/
+RUN chmod -v +x /etc/service/*/run && chmod -v +x /etc/my_init.d/*.sh
+
 # set volumes
 VOLUME /config /downloads /incomplete-downloads
 
 # expose ports
 EXPOSE 8080 9090
 
-# adding custom files
-ADD services/ /etc/service/
-ADD init/ /etc/my_init.d/
-RUN chmod -v +x /etc/service/*/run
-RUN chmod -v +x /etc/my_init.d/*.sh