Stop binding audio devices exposed by sndiod to physical devices

This a shift towards a new model: clients connect to logical devices
(created with -s option) then the server routes data to/from the
underlying physical device (registered with -f option). The binding
may be changed at run-time with the server.device control exposed by
sndioctl(1).

As audio devices exposed by sndiod(8) are not bound to fixed physical
devices anymore, the physical audio device number component of
sndio(7) descriptors was removed.

fixes, help from and ok denis, edd

When opening a device, loop over the alternate devices list in the
worker process instead of the helper process. It is simpler this way
and allows the worker to properly log which device is being used.

Allow switching between devices without disconnecting clients.

The new -F option allows alternate device to be specified. If the
device is disconnected, the one given with the last -f or -F options
will be used instead. Similarly, the new -Q option allows an alternate
MIDI port to be specified.

ok mpi@

Fix spacing and comments, no code change.

Many typos in comments. From Michael W. Bombardieri. Thanks.

Assert we're not freeing buffers we didn't allocate

Make code fit in 80 columns, remove trailing spaces & tabs.

Remplace aucat server by a new sndiod daemon aimed to be simpler
smaller and faster than aucat. It's a drop in replacement with the
following exceptions that don't affect the default setup:
- The sample rate and the encoding are a per-device parameters
thus -r and -e options must precede the corresponding -f option
- MIDI thru boxes are dynamically created and no -M option
is required anymore, so -M was removed.
- MIDI ports are exposed with a new ``midi/N'' name, rather
than abusing MIDI thru boxes.
with help from armani@, ok deraadt@

When opening a device, loop over the alternate devices list in the
worker process instead of the helper process. It is simpler this way
and allows the worker to properly log which device is being used.

Allow switching between devices without disconnecting clients.

The new -F option allows alternate device to be specified. If the
device is disconnected, the one given with the last -f or -F options
will be used instead. Similarly, the new -Q option allows an alternate
MIDI port to be specified.

ok mpi@

Fix spacing and comments, no code change.

Many typos in comments. From Michael W. Bombardieri. Thanks.

Assert we're not freeing buffers we didn't allocate

Make code fit in 80 columns, remove trailing spaces & tabs.

Remplace aucat server by a new sndiod daemon aimed to be simpler
smaller and faster than aucat. It's a drop in replacement with the
following exceptions that don't affect the default setup:
- The sample rate and the encoding are a per-device parameters
thus -r and -e options must precede the corresponding -f option
- MIDI thru boxes are dynamically created and no -M option
is required anymore, so -M was removed.
- MIDI ports are exposed with a new ``midi/N'' name, rather
than abusing MIDI thru boxes.
with help from armani@, ok deraadt@

Allow switching between devices without disconnecting clients.

The new -F option allows alternate device to be specified. If the
device is disconnected, the one given with the last -f or -F options
will be used instead. Similarly, the new -Q option allows an alternate
MIDI port to be specified.

ok mpi@

Fix spacing and comments, no code change.

Many typos in comments. From Michael W. Bombardieri. Thanks.

Assert we're not freeing buffers we didn't allocate

Make code fit in 80 columns, remove trailing spaces & tabs.

Remplace aucat server by a new sndiod daemon aimed to be simpler
smaller and faster than aucat. It's a drop in replacement with the
following exceptions that don't affect the default setup:
- The sample rate and the encoding are a per-device parameters
thus -r and -e options must precede the corresponding -f option
- MIDI thru boxes are dynamically created and no -M option
is required anymore, so -M was removed.
- MIDI ports are exposed with a new ``midi/N'' name, rather
than abusing MIDI thru boxes.
with help from armani@, ok deraadt@

Fix spacing and comments, no code change.

Many typos in comments. From Michael W. Bombardieri. Thanks.

Assert we're not freeing buffers we didn't allocate

Make code fit in 80 columns, remove trailing spaces & tabs.

Remplace aucat server by a new sndiod daemon aimed to be simpler
smaller and faster than aucat. It's a drop in replacement with the
following exceptions that don't affect the default setup:
- The sample rate and the encoding are a per-device parameters
thus -r and -e options must precede the corresponding -f option
- MIDI thru boxes are dynamically created and no -M option
is required anymore, so -M was removed.
- MIDI ports are exposed with a new ``midi/N'' name, rather
than abusing MIDI thru boxes.
with help from armani@, ok deraadt@

Many typos in comments. From Michael W. Bombardieri. Thanks.

Assert we're not freeing buffers we didn't allocate

Make code fit in 80 columns, remove trailing spaces & tabs.

Remplace aucat server by a new sndiod daemon aimed to be simpler
smaller and faster than aucat. It's a drop in replacement with the
following exceptions that don't affect the default setup:
- The sample rate and the encoding are a per-device parameters
thus -r and -e options must precede the corresponding -f option
- MIDI thru boxes are dynamically created and no -M option
is required anymore, so -M was removed.
- MIDI ports are exposed with a new ``midi/N'' name, rather
than abusing MIDI thru boxes.
with help from armani@, ok deraadt@