`calculateAdjustedUrl()` now performs file revving (and checks for existence) on image/font files included in CSS

New task to determine the critical 'above the fold' CSS required for a
page which should then be moved inline
Addition of htaccess file for file revving
Inclusion of new option (`remotePlatform`) for SFTP plugin to prevent
errors on upload
New plugin 'tap' added to determine what file is currently in the pipe