portable_audio_player.type,access_method

[Jeff Mitchell]

The 10-usb-music-players.fdi file has for each device a 
portable_audio_player.access_method key which is defined in the spec as 
mandatory, as well as portable_audio_player.type key that isn't in the 
spec at all.  Both are defined as strings.

I've run into a situation where both libifp and libmtp claim they can 
play the iRiver T10.  I'm trying to get more information, such as 
whether this is always true, or only with certain firmware revisions (in 
which case if they're exported I can try to match against that) or what, 
but there's also always the possibility that in the future more players 
will come up with more than one access_method.

So I'm wondering whether both of those keys should be changed to a 
strlist to accommodate this possibility.  Thoughts?

--Jeff