Settings: lockscreen wallpaper crash fix

If a user backs out fast enough after setting a
custom wallpaper, the fragment becomes detached
from the activity, so any calls to getActivity()
were throwing exceptions.

The solution is to use the application Context
for toassts to still inform the user of the
status, and not update any UI elements
after the fragment is no longer attached.

Change-Id: Ia9f61184fb484d3af25565bc3c56e8b7b63ff4eb
Signed-off-by: Roman Birg <roman@cyngn.com>
Settings: remove screen-off animation checkbox

Instead of having a separate checkbox on whether to
enable an animation, let's collapse it into the listview
preference. Now the user is presented with 3 options:

* Disabled
* Electron beam
* Fade out

Change-Id: I8bdcfbf5eba6b639eecabe22ad9b78b642f636df
Signed-off-by: Roman Birg <roman@cyngn.com>
Merge "Settings: remove screen-off animation checkbox" into cm-11.0
Merge "Settings: lockscreen wallpaper crash fix" into cm-11.0
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0