Add elfeed-search-date-format defcustom (fix #96).
Add elfeed-search-date-format defcustom (fix #96).

Allows users to cleanly specify their own date formats via a simple
customization variable.

holomorph/elfeed,seblemaguer/elfeed,daimrod/elfeed,holomorph/elfeed,skeeto/elfeed,seblemaguer/elfeed,algernon/elfeed,emacsmirror/elfeed,algernon/elfeed,skeeto/elfeed,emacsmirror/elfeed,daimrod/elfeed