Added install_clean.sh utility

image/bin/install_clean.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+#  Apt installer helper for Docker images
+
+set -e
+
+echo "Installing $*"
+apt-get -q update && apt-get -qy install $* \
+    && apt-get -qy autoremove \
+    && apt-get clean \
+    && rm -r /var/lib/apt/lists/*

image/utilities.sh

@@ -9,3 +9,6 @@ ln -s /usr/bin/vim.tiny /usr/bin/vim
 
 ## This tool runs a command as another user and sets $HOME.
 cp /bd_build/bin/setuser /sbin/setuser
+
+## This tool allows installation of apt packages with automatic cache cleanup.
+cp /bd_build/bin/install_clean.sh /sbin/install_clean.sh