[Adapt]Add OAL and implement Bluez HAL lib

[Adapt]Add OAL and implement Bluez HAL lib

This patch does following-

1/Create HAL or Hardware Abstraction Layer
 in Tizen BT framework which serves as the main
 stack abstraction layer. HAL interfaces are
 adopted from Bluez for Android(BFA) project.
 In case of Bluez, HAL implementation  will
 handle conversion of API calls to Bluez DBUS
 method calls and also converting DBUS events
 to API callbacks to HAL user.

2/Add BT OAL (Open Source Adaptation Layer)
 This layer will serve a stack independent
 interface beneath Tizen bt-service. All
 stack specific events will be converted to
 OAL specific events and dispatched to Tizen
 bt-service. Similary this layer will hide the
 internals of HAL (hardware abstraction layer)

3/bt-service links BT OAL library. bt-service main
 triggers BT OAL library loading which further
 dynamically loads BlueZ HAL library.

Dlogutil log extract
===================================================
oal-manager.c: load_hal_lib(134) > Tizen Platform BT chip: Tizen Platform HAL library will be loaded
oal-manager.c: load(177) > Loading Library: /usr/lib/libbluetooth.default.so
oal-manager.c: load(225) > loaded HAL id=bluetooth libpath=/usr/lib/libbluetooth.default.so hmi=0xb6f84d9c handle=0xb5301100
bt-hal-bluetooth.c: open_bluetooth(288) >
oal-manager.c: load_hal_lib(149) > HAL Library loaded successfullly
bt-service-core-adapter.c: __bt_post_oal_init(101) > OAL initialized, Init profiles..

Change-Id: Ibb50c658a4b44c4528757d41fb6198dfa85e6f05
Signed-off-by: Anupam Roy <anupam.r@samsung.com>