Message:
Use User.downloaded_file() to do "all the things"
The User.downloaded_file() method has been enhanced to accept a directory
code and a filename to do "all the things" expected after a file has been successfully downloaded. Use the method.
Message:
Prevent download if !dir is_exempt and file credits > user
total credits.
Set an 'error' property on reply if file not found or not
enough credits.
Message:
Don't prevent default click thing from doing its click thing.
(Jump back to #fTelnet anchor when doing the click thing on
a clickable click thing to do the thing.)
Complaint courtesy of Android8675309