Urgent release containing security fix to a library included with Nameless

• Update API language terms
• Improve register API method success message
• Fix Buycraft synchronisation
• Allow modifying package descriptions within the Donate addon
• Fix incorrect link following MCAssoc validation
• Update lower case addon name in link
• Keep custom package descriptions on donation sync
• Remove containers from global messages
• Fix incorrect custom avatar size in forums
• Update plugin link within AdminCP Help page
• Add getNotifications method to API
• Add updateUsername method to API
• Update included library