Update PHPDoc

Change-Id: I4b33e950e6a1c0bd76f8efff1bcffca4fb0d523e
Rename TranslatablePage::removeTags to unmarkTranslatablePage

Also update callers.

Change-Id: I63630b0adf4b81126fc2dd482bf78f4b020dd65f
Update file comment

Change-Id: I24cf3065baede83dded21af824b56bdffe0584d7
Merge changes I24cf3065,I63630b0a,I4b33e950

* changes:
  Update file comment
  Rename TranslatablePage::removeTags to unmarkTranslatablePage
  Update PHPDoc