Bug 51194: Localize the publication date in the metadata.

This adds functionality to localize publication dates, which can
be either a year, a month and a year, or a day, month, and year.
This solution seems a bit... hacky... any suggestions would be
very welcome.

Change-Id: I21f750c3f3c66d4fbf1d6a88a13dad90beaa5dea
Merge "Bug 51194: Localize the publication date in the metadata."