att_db_util: fix permission encoding

att_db_util: added security requirement arguments to creator functions

att_db_util: fix flags for CCC

att_db: add att db version as first byte, report error if version differs (also works for older db without version byte)

att: drop unused ATT_DB_PERSISTENT_WRITE_CCC

att_db_util: return attribute handle for new servics, improve header documentation

att_db_util.c: fix include path

att_db_util: add functions to create descriptors. document how to calculate cccd attribute handle

Fixes bug where the att_db would not be updated if realloc returnes a new chunk of memory.

att_db: introduce PERSISTENT_WRITE_CCC, add to CCC ATT handle

compile_gatt+att_db+att_db_util: make Client Characteristic Configuration readable without authentication but require permissions for write

tool: add update_filename.py that adds __BTSTACK_FILE__ to every .c file for use with debug output instead of __FILE__

fix common realloc mistake

add classic/core.h and ble/core.h, add ENABLE_CLASSIC where missing

att -> att_db

util.h: rename swapX into reverse_x

use little/big_endian_read/store_16/24/32

fix missing bstack_ for struct data_source and struct timer. utils->btstack_util

prefix debug with btstack_

merge from master

fix paths after source reorg

split sources into core, ble, and classic