BPD tests: check all specified commands known
BPD tests: check all specified commands known

The current MPD spec is several versions ahead of BPD. These tests just
compare the full specified list of commands against what BPD claims to
support (without actually testing their implementations). It's handy as
a measure of progress against the specification, but can perhaps be
dropped later once all of the individual protocol methods have tests.

shamangeorge/beets,shamangeorge/beets,ibmibmibm/beets,jackwilsdon/beets,SusannaMaria/beets,sampsyo/beets,sampsyo/beets,beetbox/beets,sampsyo/beets,jackwilsdon/beets,sampsyo/beets,SusannaMaria/beets,beetbox/beets,jackwilsdon/beets,SusannaMaria/beets,ibmibmibm/beets,ibmibmibm/beets,shamangeorge/beets,beetbox/beets,SusannaMaria/beets,jackwilsdon/beets,ibmibmibm/beets,shamangeorge/beets,beetbox/beets