DirectSound: use calloc for aout_stream_sys_t

Fix a crash occurring when CreateDSBufferPCM() fails in Start() and
afterwards Stop() uses uninitialized pointer values when releasing
objects.

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
DirectSound: avoid double call to release function

If Start() failed, IDirectSound_Release() was called twice.

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net> with changes
Revert "auhal: rework channel mapping for analog surround output"

This reverts commit c3bb23cd68f36ea37cf8d6ecb7cc187cd47c1c38.
Revert "auhal: fix wrong analog 5.1 channel ordering (close #8589)"

This is superseded by a proper fix.
This reverts commit fa396d194fa58097223475d8038605f10a5041c5.
auhal: simplify switch by mapping with an array
auhal: correctly fix channel ordering by setting the correct scope.

fixes #10125, #10199
auhal: rename layout variable to make more clear that this is the input layout
mmdevice: add missing initializer (fixes #10775)
mmdevice: improve diagnostics
npapi: sensible prefix
npapi: correct pkg-config paths
macosx: add NSFullScreenWindowMask to compatibilityFixes.h and avoid NSAnimationContext warning
configure: unbreak cross-pkg-config support with contrib

cross-pkg-config tools have a correct default search path. The contrib
path should complement it, not replace it. If the caller intends to
(ab)use the native pkg-config for cross-compilation, the caller is
responsible for selecting an adequate default path, not VLC configure,
just as with every other build tools.
mmdevice: guard against out of range values
wasapi: fix S/PDIF check
wasapi: fix TimeGet()
mmdevice: merge volume/mute update code and fix initial volume
mmdevice: print endpoint volume range to debug
mmdevice: override endpoint volume to allow amplification

This works more or less like SNDVOL (and like PulseAudio with flat
volumes not disabled): the VLC volume represents the product of the
endpoint volume by the simple volume.
mmdevice: implement audio policy callback (fixes #7204)