QuickBoot: enable QuickBoot Settings UI

Add QuickBoot enable item in DevelopmentSettings.

Change-Id: Id2aaec4ad3e85f51235db4c25d49136a26502e20

Conflicts:

	res/xml/development_prefs.xml
	src/com/android/settings/DevelopmentSettings.java
Merge branch 'kitkat' of https://github.com/AOSPA/android_packages_apps_Settings into kitkat