BUG/MINOR: lua: Map.end are not reliable because "end" is a reserved keyword

This patch change the names prefixing it by a "_". So "end" becomes "_end".
The backward compatibility with names without the prefix "_" is assured.
In other way, another the keyword "end" can be used like this: Map['end'].

Thanks Robin H. Johnson for the bug repport

This should be backported in version 1.6 and 1.7
diff --git a/src/hlua.c b/src/hlua.c
index bfb9c94..41f1805 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -7258,6 +7258,10 @@
 	/* register pattern types. */
 	for (i=0; i<PAT_MATCH_NUM; i++)
 		hlua_class_const_int(gL.T, pat_match_names[i], i);
+	for (i=0; i<PAT_MATCH_NUM; i++) {
+		snprintf(trash.str, trash.size, "_%s", pat_match_names[i]);
+		hlua_class_const_int(gL.T, trash.str, i);
+	}
 
 	/* register constructor. */
 	hlua_class_function(gL.T, "new", hlua_map_new);