dist: added script for merging Arduino sketches

dist/tools/arduino/pre_build.sh

+#!/bin/sh
+
+# check if at least the application dir and one sketch is given
+if [ $# -lt 2 ]
+then
+    echo "[Arduino pre-build] Error: not enough arguments given"
+    exit 1
+fi
+
+# 'consume' the application and arduino directories (first argument)
+SRCDIR=$1
+shift
+APPDIR=$1
+shift
+
+# create temporary file and put in the file header
+cat ${SRCDIR}/pre.snip > ${APPDIR}/_sketches.cpp
+# loop through the given sketches and include them into the temp file
+for sketch in $@
+do
+    cat ${sketch} >> ${APPDIR}/_sketches.cpp
+done
+# and prepend the file with the arduino bootstrapping code
+cat ${SRCDIR}/post.snip >> ${APPDIR}/_sketches.cpp