Bluedroid use a set of timer function pairs such as btu_start_timer/btu_stop_timer, btu_sys_start_timer/btu_sys_stop_timer for use, in a lack of timer release functions. Thus the timers may be exhausted after some event sequence such as repetition of connection/reconnection with different devices. The maximum timer number used in bluedroid is given by ALARM_CBS_NUM which is 30 for now. This bugfix borrowed some update from bluedroid in Andoroid 7.0, which add timer release functions which promote the recycle of timer resources.
# Conflicts:
# components/bt/bluedroid/stack/btu/btu_task.c
# components/bt/bluedroid/stack/gatt/gatt_main.c
# components/bt/bluedroid/stack/rfcomm/port_utils.c
# components/bt/bluedroid/stack/rfcomm/rfc_utils.c
1. move the app demo code to example
2. move the header files to correct path
3. move profile to profiles directory and seperate esp&std
4. some other codes
5. needs continue to cleanup the code
