Extract and show license key

List of available licenses is pre-extracted from UploadWizard
MediaWiki extension. This should eventually be switched to use
some live query to the site configuration.

The license display is more or less localizable, for known templates.
Unrecognized templates specified as parameters to {{self}} will be
recognized (unlocalized) but others may not be.

Change-Id: I9df5fe807798a191a3bb0a45464760c75f19e366
Merge "Extract and show license key"