Update VisualEditor to latest 1.23wmf12 for cherry-picks

Changes:
* 5bb28b8 - Fix 'use existing reference' list rendering

Change-Id: I1214378b5452b375b26cf97f7eeb89fa78ac491e
Merge "Update VisualEditor to latest 1.23wmf12 for cherry-picks" into wmf/1.23wmf12