Update Widget API names and parameter names

banner -> bannerForPub
resource -> dataPackageForPub

Parameters are now referrer and pubId
Updates to Widget API java code

Handle DOIs in http://dx.doi.org/... format
Rename parameters to be consistent with cocoon
Generate 404 page when no data package found

WidgetBannerAction throws ResourceNotFoundException when not found
widgets.xmap handles errors and generates 404 page
Merge branch 'trello-13' into dryad-dev