panu_demo: fix unused warning

example: use sdp_create_service_record_handle() for sdp record and assert sdp record buffer is large enough, fixes #489

examples: unify status stdout format

example: init SM if LE supported to avoid issue with Android Cross-Transport Key-Derivation

license: update text

panu_demo: avoid unused var warnings if client mode is disabled

docu: copy editing examples titles

docu: updated titles of examples

bnep: BD_ADDR is stored in little-endian format for all BNEP_EVENT_*

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

example/panu_demo: register NAP service with BNEP when implementing server

example/panu_demo: use ENABLE_PANU_CLIENT to switch to PANU client mode

example/panu_demo: setup SDP and register PANU SDP Record

examples: panu_demo.c + sdp_bnep_query.c, don't free local variable

example/panu_demo: use static buffer for service names

sdp queries: check if DES element exist before reading it

example: register for events after setting up the stack, register for hci events after sm_init()

network: fix compile, add btstack_network_get_name

network: extract POSIX network code into btstack_network_posix and use in panu_demo

update examples docu

panu_demo: fix SDP remote log output

panu_demo: enable tun interface read callback

panu_demo: also log bnep send

panu_demo: request can send now, log received network packets

panu_demo: prefer NAP over PANU