Extended power menu: reboot & screenshot options

Change-Id: I3fb3c0a2d0a4efedaf4b3349a404b357a3cb5621

Conflicts:
	policy/src/com/android/internal/policy/impl/GlobalActions.java

 Author:    David van Tonder <david.vantonder@gmail.com>
 Changes to be committed:
	modified:   core/java/android/view/WindowManagerPolicy.java
	new file:   core/res/res/drawable-hdpi/ic_lock_reboot.png
	new file:   core/res/res/drawable-hdpi/ic_lock_screenshot.png
	new file:   core/res/res/drawable-ldpi/ic_lock_reboot.png
	new file:   core/res/res/drawable-ldpi/ic_lock_screenshot.png
	new file:   core/res/res/drawable-mdpi/ic_lock_reboot.png
	new file:   core/res/res/drawable-mdpi/ic_lock_screenshot.png
	new file:   core/res/res/drawable-xhdpi/ic_lock_reboot.png
	new file:   core/res/res/drawable-xhdpi/ic_lock_screenshot.png
	modified:   core/res/res/values/arrays.xml
	modified:   core/res/res/values/public.xml
	modified:   core/res/res/values/strings.xml
	modified:   policy/src/com/android/internal/policy/impl/GlobalActions.java
	modified:   services/java/com/android/server/power/ShutdownThread.java
	modified:   services/java/com/android/server/wm/WindowManagerService.java