[AD] Audio plugin function names

[Evert Glebbeek <eglebbk@xxxxxxxxxx>]

Sorry if anyone gets this twice, my previous copy doesn't seem to  
have come through...

Right now in the audio plugin, functions are named
al_sample_play, al_sample_stop, al_voice_destroy,  
al_sample_data_destroy etc.
Shouldn't those be called al_play_sample, al_stop_sample,  
al_destroy_voice, al_destroy_sample_data etc. to be consistent with  
the rest of the API?
The accodec plugin has "al_load_sample", which does follow the  
"verb_noun" naming pattern.
Right now the audio plugin(s) doesn't (don't) seem to follow a  
consistent naming scheme, neither internally nor when compared to the  
rest of the library. If we want "al_addon_verb_noun" (as in  
"al_font_load_font", which admittedly isn't the prettiest name out  
there) then maybe it should be "al_audio_play_sample" etc.
Right now it's a bit jarring compared with the rest of the API.

Evert