I missed the feature to edit multiple users or project at once.

E.g. I copied a Mantis-System and wanted to delete all projects and users except a few. I had to open the page for every project or user and delete it "manually" - which was quite exhausting.

Needed features:

• Checkboxes at the overview-pages (e.g. manage_user_page.php and manage_proj_page.php) and a button for actions to do with the selected ones (e.g. 'Delete')
• a button or checkbox to select/unselect all