Updated mediawiki/extensions
Project: mediawiki/extensions/Scribunto  40b8bd2caaf055bbf869df040f42aa20b53a643c

Add comments and remove trailing whitespace

Clean up trailing whitespace from all of our code, and add comments
indicating that apparently unused variables are ScopedCallbacks.

Change-Id: I8e5997797cc7b1c64c5351ec112a18f30edc8fef