The device is not know at SelectConfiguration time, so the settings
argument in select_config is currently unused. Pass on a global settings
dict instead, so that codec parameters can be configured.
Also add settings argument to caps_preference_cmp.
Bump codec API version.
Add a flag A2DP_CODEC_FLAG_SINK to incidate a sink endpoint.
Also enum_config and caps_preference_cmp may need to know whether the
codec is being configured for SRC or SNK. Also add the flags argument to
init_props.
Bump codec API version.
The file name "lc3.h" in the ETSI LC3plus package may conflict with the
actual LC3 codec, so try to find a file "lc3plus.h" instead. Also try
to find a pkg-config dependency for it first (in which case use lc3.h,
assuming it's in different directory). This can be fine tuned, if
something starts to package that library.
