Convert doat to an internal command

- Trivial plugin
- Useful for many users
- Was under a dumb license

src/common/plugin.h

@@ -179,5 +179,6 @@ int plugin_emit_keypress (session *sess, unsigned int state, unsigned int keyval
 GList* plugin_command_list(GList *tmp_list);
 int plugin_show_help (session *sess, char *cmd);
 void plugin_command_foreach (session *sess, void *userdata, void (*cb) (session *sess, void *userdata, char *name, char *usage));
+session *plugin_find_context (const char *servname, const char *channel, server *current_server);
 
 #endif