tool/compile_gatt: support multiple process passes

tool/compile_gatt: fix tool permissions

tool/compile_gatt: normalize paths, use os specific path separators

compile_gatt: document how .h was generated

compile_gatt: add support for WRITE_AUTHENTICATED_SC and READ_AUTHENTICATED_SC flags

compile_gatt: Allow enable Notifications/Indication with Write Command. Fixes issue with some Android devices

compile_gatt: add additional paths for .gatt files using -I

compile_gatt: fix parsing of CHARACTERISTIC_USER_DESCRIPTION, issue #23

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

compile_gatt: pretty print security settings in generated file

compile_gatt: define independent security requirements for read and write operations

att_db: detect persistent ccc by attribute uuid instead of explicit flag

att_db: introduce PERSISTENT_WRITE_CCC, add to CCC ATT handle

compile_gatt: fix flags for ccc

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

gatt_compiler: fix typo on CLIENT_CHARACTERISTIC_CONFIGURATION

move GATT services into src/ble/gatt-service

GATT Compiler: support #import <..> and ".." directives

GATT Compiler: align comments

add defines for start and end handle of each service

GATT Converter: resolve UUIDs from src/bluetooth_gatt.h

compile-gatt.py -> compile_gatt.py