Implement bluetooth API based on Tizen bluetooth stack

BUG=XWALK-1065

Signed-off-by: Corentin Lecouvey <corentin.lecouvey@open.eurogiciel.org>
Those lines are useless ! I assume Bluez4/5 backends were functional in desktop mode. 
There is absolutely no added value to call bt_initialize() in Bluez backends if Tizen C API is not used in this backend.

If I re-add Tizen C API calls in Bluez backends, it means that I need to create 2 new "hybrid" backends (Tizen C API + Bluez4/5) and this is not the goal...