Settings: Create SAR level preference, allow overlay.

Change-Id: I1af616696702f72b8a6276b3b01e940d61735137

Conflicts:
	res/values/liquid_strings.xml
Change Regulatory Info Activity to prefer string over image

Change-Id: I9ea5c2bf469af8f654ec4e4bb4f2a8a5738e6a95
Support all known DPI values

Extend the dpi range to complete the table, as you can see here xxhdpi goes from 480 to 639 than becomes xxxhdpi at 640
http://developer.android.com/guide/practices/screens_support.html

Support the devices that use xxxhdpi (e.g LG G3) or people who use a modified DPI higher than 480 in build.prop to get rid of the "unknown" value being returned

Change-Id: Iac19ef51a840cf118f1a72fc5bf5f3406e042282
Modify the Development shortcut help text

Change-Id: I4e41a1df4b929630e0f759812ab0b53280a4d722