This patch adds proper selection of the Bluetooth backend. The backend
is configurable via environment property 'ro.moz.bluetooth.backend'. The
default value is still Bluedroid.
On systems that are not Android 4.2 or later, the code does not return
a backend. These systems should use BlueZ instead.
This patch is based on bug 1065336, patch [01] and bug 1124565,
patch [01]. It also contains an extra fix in 'moz.build' to set
the pre-processor constant 'MOZ_B2G_BT_DAEMON'.
This patch moves BluetoothInterface.{cpp,h} to the generic section
of Gecko's Bluetooth code, and the Bluedroid implementation into
the new files BluetoothHalImplementation.{cpp,h}.
BluetoothHalImplementation.{cpp,h} contains all Bluedroid-specific
code. The classes in BluetoothInterface.{cpp,h} are now interfaces
for Gecko.
--HG--
rename : dom/bluetooth2/bluedroid/BluetoothInterface.cpp => dom/bluetooth2/bluedroid/BluetoothHALInterface.cpp
