add cast to getting security level

fix c99 warnings for missing argument of functions with no arguments, fix more warnings

mark channel as invalid before sending connection response decline or disconnection response

Stop using pointer to array for bd_addr_t and link_key_t

support for L2CAP Unicast Connection Data

streamline copyright headers

improve log messages for l2cap rx timer

Initialise l2cap channel struct with 0 after allocating memory (make valgrind happy)

mark l2cap signal response pending to avoid sending it multiple times with synchronous HCI Transport implementation

only disconnect HCI connection in case of security block (fixes disconnect for non-existing service or resoucees full)

L2CAP: validate packet size with remote MTU -> log_error

fixed tracking of l2cap, rfcomm services and channels

fix daemon compile without BLE support

le central handle connection update params

use HCI_ACL_PAYLOAD_SIZE to determine L2CAP MTU

use hci_acl_le_data_buffer_length to get max le l2cap mtu

fix remote_mtu and flush_timeout in L2CAP_EVENT_CHANNEL_OPENED

removed cast for btstack_memory_X_get calls

l2cap and rfcomm close connection functionality was moved to deamon

fix outgoing l2cap connections (regression 'hci_number_free_acl_slots: handle 0x0000 not in connection list')

use log_info instead of printf, remove trailing newline from log calls

fix compile

add l2cap_max_le_mtu

replace hci_number_free_acl_slots with hci_number_free_acl_slots_for_handle

provide l2cap_can_send_fixed_channel_packet_now that takes handle as input