Handles everything on the "Download New Packages" screen.

• Requires the admin_forum permission
• Part of the manage_packages adminIndex
• Loads the Packages template and language files
• Accessed at index.php?action=packageget in 1.0.x and 1.1.x
• Accessed at index.php?action=admin;area=packages;get in 2.0
• Allows you to add/remove package servers and upload new packages from your computer