Ignore book title

Titles parsed from {{Book}} templates are usually irrelevant and should be
ignored (we don't want to show the title of some book containing the image
instead of the name of the image).

Book templates will have to be ignored completely anyway (#937) so this commit
is really just about cleaning up the template parser configuration.

Also add test for extracting the title.

Change-Id: I27879afbaefe40a879a34eccdf7515a6f9bbe3e2
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/589
Merge "Ignore book title"