Dont show "Erase SD Card" when there is none

On devices with physcal, external SD Cards, the "Erase SD card"
option in in Settings/Storage is available even when there is
no SD card present, this dont make much sense since you cannot
erase a card that is absent. With this change the erase option
is bound to the mount toggle which leads to the following
consequences:

 Card present and mounted -> Erase enabled
 Card present but unmounted -> Erase enabled
 No card present -> Erase disabled
 Card present and MTP attached -> Erase disabled

Change-Id: I756ae8af3e0565febaf940df5f4991dd89105bd9
Fix elapsed time formatting.

We should extend DateUtils to provide this kind of elapsed time
formatting via icu4c, but for now let's at least fix our
arithmetic.

Bug: https://code.google.com/p/android/issues/detail?id=61479
Change-Id: I6c087dbb9fdbff0a21d9243d239126fee180454c
Bluetooth: Don't set a null alias before unpairing

* This causes the unpair action to throw a null pointer exception and
  bring down the Settings app. Don't do this.

Change-Id: I0c60437f5ea934385a037a464743e24c9d341aca
User-selectable camera click sound [1/3]: (stock(bloop)/realistic/disabled)

ps21: change listview key so the internal preference persistence doesn't try to turn a string into a boolean behind the scenes.
ps22: it might help if we make SoundSettings handle preferenceChanged events, mmmmkkkkkaaaayyyyyy?

Originally: option to disable camera sounds (1/3) by sethyx

Change-Id: Ibc61515e78ecfa1d438b3770b02284c4cb9d7f23
Signed-off-by: nuclearmistake <nuclearmistake@gmail.com>
Signed-off-by: scott <scott@ubuntu>

Conflicts:
	res/values/vanir_arrays.xml
	res/values/vanir_strings.xml
minimum vibration duration 2/2

Change-Id: I0d1945c527cb7e420209d609dc6d9007a54c7444
Signed-off-by: scott <scott@ubuntu>