Reorganize and clean up lock screen section

- Move the option for enabling widgets to the top of the widgets header,
  as it is 1) the most important option in that section and 2) most
  likely what the user's going to be looking for first.

- Use a simple "custom widgets" title for enabling widgets instead
  of the verbose "widget pager" term.

- Shorten and simplify overly long, hard to parse space-hogging
  summaries.

- Move "slider shortcuts" out of the widgets section.

- Hide "maximize widgets" option on low RAM devices.

Change-Id: Iac1b55a6b976c5645ca7f46e7fdf0821396e1100
Forward port CM Screen Security settings (2/2)

* Lockscreen Vibrate
* Slide Lock Delay
* Menu Unlock
* Home Unlock
* Variable size pattern lockscreen
* Toggle dots/error pattern visibility

Forward port from cm-10.2, adjusted for 4.4

Change-Id: I0dda524830d8dce571910eb1fbd66d5b5af11bff