Merge branch 'develop' into feature/discard-warning

include/ajax.tickets.php

include/staff/login.tpl.php

scp/css/login.css

scp/css/scp.css

scp/images/grey_btn_bg.png

scp/images/login-background.jpg

scp/images/login-logo.png

setup/inc/header.inc.php

setup/inc/install.inc.php

setup/inc/upgrade-attachments.inc.php

setup/install.php

setup/setup.inc.php