added simple script for finding the events that are in use

* many events are not grepped due to linebreaks

scripts/list_events.sh

+#!/bin/sh
+
+set -eu
+
+BASE_DIR=$(cd "$(dirname "$0")"; pwd)
+
+grep -rh _event "$BASE_DIR/../pycam" | \
+	grep -v " def " | \
+	grep -v configure_event | \
+	grep -v expose_event | \
+	sed 's/.*_event//g' | \
+	grep '"' | \
+	cut -f 2 -d '"' | \
+	grep -E "^[0-9A-Za-z_-]+$" | \
+	sort | \
+	uniq -c
+