add snd_device_name_hint() function and initial implementation

- add snd_device_name_hint() and snd_device_name_free_hint() functions
- add snd_ctl_iface_conf_name() functions
- do not accept parameters for the plugin definition without @args section
- add defaults.pcm.dmix.card/device and dsnoop.card/device definitions
- add hints for HDA-Intel.conf, pcm/dmix.conf, pcm/dsnoop.conf and alsa.conf
- add test/namehint test utility
- doxygen related cleanups

include/local.h

@@ -259,4 +259,8 @@ void snd_config_set_hop(snd_config_t *conf, int hop);
 int snd_config_check_hop(snd_config_t *conf);
 #define SND_CONF_MAX_HOPS	64
 
+int snd_config_search_alias_hooks(snd_config_t *config,
+                                  const char *base, const char *key,
+				  snd_config_t **result);
+
 #endif