Abstract out the date formatting method so that it can be shared amongst formatters
and%2Bthe%2BReal%2BEffects%2Bof%2Bthe%2B2007%2BCredit%2BCrisis|https://libraries.psu.edu/|0||Notice: Undefined index: year in SearcherFormatter->publicationDate() (line 207 of /data/deployment/ul01prod/current/all/modules/custom/features/psulib_bento/inc/psulib_bento.SearcherFormatter.inc).
NewspaperArticlesFormatter::publicationDate
has this problem solved, so that method can be abstracted and shared somehow.
Non-critical bug.