2.521

• Fix to make upload tracking work correctly in all situations and on all systems
• Update Xterm.js to the latest version with lots of improvements and fixes
• Update Authentic theme to the latest version with various improvements and fixes:
  • Fix the support for the cloned Terminal module
  • Fix error handling for file uploads when the user is out of quota or the system is out of disk space in the File Manager module
  • Fix to stop loading full file into memory for upload check to prevent memory leak on large uploads in the File Manager module
  • Fix to permanently save the state of the navigation menu and right-side slider when toggled