add convenience script for running herbgrind

herbgrind.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+# exit on error
+set -e
+
+# determine physical directory of this script
+src="${BASH_SOURCE[0]}"
+while [ -L "$src" ]; do
+  dir="$(cd -P "$(dirname "$src")" && pwd)"
+  src="$(readlink "$src")"
+  [[ $src != /* ]] && src="$dir/$src"
+done
+MYDIR="$(cd -P "$(dirname "$src")" && pwd)"
+
+HG="$MYDIR/valgrind/herbgrind-install/bin/valgrind --tool=herbgrind"
+
+$HG "$@"