Added build date (ro.build.date from build.prop) to device info.

Change-Id: I5e19ee04de5c26822e171d4af8f4bfc052be9b74

Conflicts:
	res/values/cm_strings.xml
	src/com/android/settings/DeviceInfoSettings.java
Settings: Catch NPE caused by attempting to invoke virtual method  on a null object reference

Change-Id: I86ae0f7b46b12533190228404e0bed406d85b2e6
Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>