20190223 NEW: wildcard searching using isbn prefix (ie. "978818274*")
20190207 NEW: missing feed email notification
20200310 NEW: admin panel to view subscriptions emails stats
20200326 NEW: support for main and regular bic & bisac subjects
20200406 NEW: single view of a product
20201117 NEW: updated php 5.6 to php 7.4
20210723 NEW: docx (MS Word) export
20210727 NEW: changes in productform 
20211106 NEW: related products support in product single view