make a map[] for tracking PB changes

changed.go

@@ -0,0 +1,21 @@
+package config
+
+// this package can provide a trivial way to track which
+// protobufs have been modified and need to be written to disk
+// todo: autogenpb could generate code to work with this
+
+var saveMap map[string]bool
+
+func init() {
+	// init() should be avoided, but this package and for making
+	// this small string map, it seems a sensible exception
+	saveMap = make(map[string]bool)
+}
+
+func SetChanged(name string, b bool) {
+	saveMap[name] = b
+}
+
+func HasChanged(name string) bool {
+	return saveMap[name]
+}