Pass plugin path in the settings array.

src/sudo_plugin_int.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010-2013 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 2010-2014 Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -83,6 +83,7 @@ struct io_plugin_1_1 {
 struct plugin_container {
     TAILQ_ENTRY(plugin_container) entries;
     const char *name;
+    const char *path;
     char * const *options;
     void *handle;
     union {