Make min/full even nicer

[raymondjacobson]

Add some unimplemented endpoints

g.Get("/users/:userId", app.v1User)
g.Get("/tracks/:trackId", app.v1Track)
g.Get("/playlists/:playlistId", app.v1Playlist)

(the singular versions of stuff that already exists)

And also make min/full even nicer. Now automatically everything full, gets a non-full, and does the min model type. No way to "forget" to add a non-full version now!

Tested=

make test
make apidiff

[stereosteve]

super nice.