Add slim version to about screen

Change-Id: I4d54b8dd02c3fb75eac1a5f4fffce59611555192

Conflicts:
	res/xml/device_info_settings.xml
	src/com/android/settings/DeviceInfoSettings.java

 Author:    Griffin Millender <griffinn.millender@gmail.com>
 Changes to be committed:
	modified:   res/values/slim_strings.xml
	modified:   res/xml/device_info_settings.xml
	modified:   src/com/android/settings/DeviceInfoSettings.java