Tag: Change Tag::appendContent() signature in PHP to match other methods
Tag: Change Tag::appendContent() signature in PHP to match other methods

This makes all 3 methods appendContent(), prependContent(), and
removeContent() look and behave the same.

Change-Id: I6fac39ff5abc7e3ce97fd35fd8ea4900424100c6

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui