[fixes #1918] toString now supports a configkey to tell it how to deal with super.

test/transform/resource/before/ToStringAutoSuper.java

@@ -0,0 +1,8 @@
+//CONF: lombok.toString.callSuper = CALL
+@lombok.ToString
+class ToStringAutoSuperWithNoParent {
+}
+
+@lombok.ToString
+class ToStringAutoSuperWithParent extends ToStringAutoSuperWithNoParent {
+}