Settings: Simplified Chinese translations

Added stylus-related translations, as well as modifications to existing
strings.

Patch Set 2: Undo an accidental change to the lock_after_timeout_summary
string in http://review.cyanogenmod.org/#/c/22753/. My mistake.

Patch Set 3 & 4: A slight modification.

Patch Set 5: Corrected a typo.

Patch Set 6: Slight modification again.

Change-Id: I17b12e698364ea571b32404b061d6943fe2003c9