added release archive preparation script

prepare-release.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+# Release archive builder for Bananarchy
+BA_TARGET="$1"
+BA_VER=$(cat rootfs/etc/os-release | grep VERSION_ID | cut -f 2 -d '"')
+RELDIR="bananarchy-${BA_TARGET}-${BA_VER}"
+./rebuild-image.sh $BA_TARGET
+mkdir $RELDIR
+cp images/bananarchy-${BA_TARGET}.img ${RELDIR}/
+cp bootloader/lk2nd-msm8909.img ${RELDIR}/
+zip -9r ${RELDIR}.zip $RELDIR
+rm -rf $RELDIR
+echo "Release $BA_VER for $BA_TARGET packed into ${RELDIR}.zip"