Settings LightSettingsDialog: update led on text change

Change-Id: I135f37829b9b4fb2166afac9d9531b76a62f3ef7
Bring back Camera widget option for tablets

Starting from ~2014-01-29, Camera widget is also shown on tablets.
That's actually a good thing, so let's bring back the option to
make it configurable.

Change-Id: I56f51b70eca4ef528dc91a13c658d33d43a90dec