Bluetooth: Release pan proxy object while coming out from tethering menu

A case where user is going into tethering menu & coming out repeatedly
(2000 iterations) irrespective of Bluetooth state(ON or OFF). Setting
application get crashed after 1386 iterations. Each time TetherSetting
& BluetoothPan object were leaked, because connection of the pan profile
proxy to the Service was not closed by tetherSetting while coming out
from tethering menu. Releasing the pan proxy object while coming out
from tethering menu to avoid memory/objects leak.

Change-Id: I06a5e1ed37a024695fddb1e95f62b72fd56510d3
CRs-Fixed: 622489
[3/3]Settings: add "Accept all files" option for incoming files via Bluetooth

  Vanilla Android requires the incoming file from Bluetooth to be certain mime-types.
  The mime-types allowed are defined in
packages/apps/Bluetooth/src/com/android/bluetooth/opp/Constants.java
  But sometimes we need to accept files that is not in the list,such as RAR archives
or APK packages.
  This patch makes "Accept all files" an option in Settings -> Bluetooth -> (Menu),
and then saves users' choice to Settings Provider database.
  This will meet users' demand as well as keep the phone from unsafe files
when users don't need to accept the files out of the mime-type whitelist.

Change-Id: I5f04d3ccb45bd5c6525b746855bd19ccc8501d32

Change-Id: Iede00c9ba944b1e376ebde3596da79b6da7f3478

Conflicts:
	res/values/slim_strings.xml