remove <stdio.h>, <stdlib.h> and printf from most core files

avrcp: rename getter functions

avrcp_target: fix compile

avrcp_target: add avrcp_target_register_set_addressed_player_handler

avrcp: use bool for wait_to_send

avrcp: improve API documentation

avrcp: use separate context for avrcp, remove handling of AVRCP_META event from controller/target

avrcp: remove commented code

avrcp: replace avrcp_target/controller_connect/disconnect with avrcp_connect/disconnect

avrcp: call avrcp_init explicitly

avrcp: move target and controller contexts to avrcp.c file

avrcp: remove redundant input parameter

avrcp: improve function name

avrcp_target: use if else chain to pick next action

volume in avrcp_target_volume_changed is reported as current value in interim response to register for volume change notifications

avrcp_target: use correct variable for sending playback status value

avrcp_target: use avrcp_target_response_setup to reduce params to avrcp_target_response_vendor_dependent_interim

avrcp_target: extract avrcp_target_response_setup

avrcp_target: only use RFC2978_CHARSET_MIB_UTF8

avrcp_target: extract avrcp_target_pack_single_element_header

ignore memcpy return value (always returns first parameter)

MISRAC2012-Rule-12.1: add suggested parentheses

MISRAC2012-Rule-12.1: add suggested parentheses

avrcp_target: increase notifications_transaction_label array to fit max notification id

Use BTSTACK_FILE__ without __ prefix (MISRAC2012-Rule-21.1)