Merge upstream develop to resolve merge conflicts

.gitignore

assets/default/about-custom-themes.md

assets/default/css/print.css

assets/default/css/theme.css

assets/default/css/theme.min.css

assets/default/less/base.less

assets/default/less/kb.less

assets/default/less/landing-page.less

assets/default/less/main-layout.less

assets/default/less/print.less

assets/default/less/reset.less

assets/default/less/theme.less

assets/default/less/ticket-forms.less

assets/default/less/ticket.less

include/.htaccess

include/class.banlist.php

include/class.canned.php

include/class.config.php

include/class.filter.php

include/class.mailfetch.php