Rename /build to /bd_build for fewer AUFS layer collissions

image/cleanup.sh

@@ -1,10 +1,10 @@
 #!/bin/bash
 set -e
-source /build/buildconfig
+source /bd_build/buildconfig
 set -x
 
 apt-get clean
-rm -rf /build
+rm -rf /bd_build
 rm -rf /tmp/* /var/tmp/*
 rm -rf /var/lib/apt/lists/*
 rm -f /etc/dpkg/dpkg.cfg.d/02apt-speedup