Add a sript to check JS validity

A simple test by nodejs that can be put inside the Git pre-commit hook
that checks for basic syntax violations.

devTools/checkJS.sh

+#!/bin/sh
+
+tmpJoinedFile=`mktemp --suffix=.js`
+
+files=$(find js src -name '*.js' -print)
+files=$(echo "$files" | sort)
+for f in $files; do
+	printf "\n/* ${f} */\n" >> "$tmpJoinedFile"
+	cat "$f" >> "$tmpJoinedFile"
+done
+
+node -c "$tmpJoinedFile"
+
+test $? -eq 0 && rm "$tmpJoinedFile"