a2dp: introduce context, move common code to avdtp.c
a2dp: wrap source functionality
a2dp: enable packet handler
a2dp: draft implemetation source open stream
avrcp: add streaming connection opened/released events
avdtp source: introduce timer for storing audio data at const fr., encode into sbc, and prepare for sending
wav_util: fix return of wav_reader_read_int16
sbc: rename sbc to msbc test
sbc: improve usage output
sbc: fix makefile
sbc: remove hardcoded bitrate
avdtp: add encode/decode sine example without using ring buffer
avdtp: move ring buffer to stream endpoint
avdtp: add encode/decode test with ring buffer
sbc: use btstack_sbc_encoder_num_audio_frames - 1 audio frame contains 1 audio sample for mono and 2 for stereo
sbc: use btstack_sbc_encoder_num_audio_frames - 1 audio frame contains 1 audio sample for mono and 2 for stereo
sbc: revert sample counting
avdtp: source sending correct audio first time
avdtp: shorter timer for audio generation gets correct stream
avdtp: set state to AVDTP_STREAM_ENDPOINT_STREAMING_W2_SEND when more data is ready
avdtp: introduce transport category as mandatory
avdtp: introduce transport category as mandatory
