Settings: Add option to scramble pin layout when unlocking (1/2).

Change-Id: I3e2c200a0a31d3c765831bc30280029a50c88051
Improve notification spam filter code.

- Follow coding style guidelines
- Replace dialog shown on click by adding the relevant information and
  the delete button to the item itself
- Minor layout tweaks
- Make the empty view more descriptive
- Add license headers

Change-Id: Ic685364087d6a093fdbb6a143a9c6ed78596b62b
Merge remote-tracking branch 'cyanogen/cm-11.0' into cm-11.0