Issue #3: Replace 'drupal' with 'backdrop' throughout PHP code.
Merge pull request #286 from quicksketch/3/drupal_backdrop_rename

Issue #3: Replace "drupal" with "backdrop" throughout code.
Issue #258: Swap out Favicon with Backdrop logo.
Merge pull request #337 from quicksketch/favicon

Issue #258: Swap out Favicon with Backdrop logo.
Issue #259: Swap in new logo throughout Backdrop CMS.
Merge pull request #338 from quicksketch/259/replace-logos

Issue #259: Swap in new logo throughout Backdrop CMS.