* Rework the seqmidi aliases.
- The 1st alias is now the Jack1 MIDI port name with alsa_midi prefix.
- This 2nd alias is basically the same as the 1st alias with the
alsa_midi prefix stripped, so that devices are listed under the ALSA
Also fixed the "capture" and "playback" port type names which were the
wrong way round.
* Rework the rawmidi alias.
Like in alsa_seqmidi.c, the 1st alias is now the Jack1 MIDI port name
with alsa_midi prefix.
* Rework pretty-name metadata.
The rawmidi and seqmidi pretty-name metadata now uses the same Jack1
port name as the 1st alias, without the alsa_midi: prefix.