ext/alsa/: Add enumerations (as GstMixerOptions). Make correct distinction between input/output tracks. Add capture/p...

Original commit message from CVS:
* ext/alsa/Makefile.am:
* ext/alsa/gstalsamixer.c: (gst_alsa_mixer_interface_init),
(gst_alsa_mixer_build_list), (gst_alsa_mixer_get_volume),
(gst_alsa_mixer_set_volume), (gst_alsa_mixer_set_mute),
(gst_alsa_mixer_set_record), (gst_alsa_mixer_set_option),
(gst_alsa_mixer_get_option):
* ext/alsa/gstalsamixer.h:
* ext/alsa/gstalsamixeroptions.c:
(gst_alsa_mixer_options_get_type),
(gst_alsa_mixer_options_class_init), (gst_alsa_mixer_options_init),
(gst_alsa_mixer_options_new):
* ext/alsa/gstalsamixeroptions.h:
* ext/alsa/gstalsamixertrack.c: (gst_alsa_mixer_track_new):
* ext/alsa/gstalsamixertrack.h:
Add enumerations (as GstMixerOptions). Make correct distinction
between input/output tracks. Add capture/playback private flag.
Use flag to decide on whether to set capture or playback volumes
or switches. Use playback and record switches.
* gst-libs/gst/mixer/Makefile.am:
* gst-libs/gst/mixer/mixer-marshal.list:
* gst-libs/gst/mixer/mixer.c: (gst_mixer_class_init),
(gst_mixer_set_option), (gst_mixer_get_option),
(gst_mixer_mute_toggled), (gst_mixer_record_toggled),
(gst_mixer_volume_changed), (gst_mixer_option_changed):
* gst-libs/gst/mixer/mixer.h:
* gst-libs/gst/mixer/mixeroptions.c: (gst_mixer_options_get_type),
(gst_mixer_options_class_init), (gst_mixer_options_init),
(gst_mixer_options_dispose):
* gst-libs/gst/mixer/mixeroptions.h:
Add GstMixerOptions.
* sys/oss/gstosselement.c: (gst_osselement_class_probe_devices):
Rename Audio Mixer to OSS Mixer (similar to Alsa Mixer). Fix
broken device detection on computers with multiple OSS sound
cards.