Add ability to log who downloads a file from Send

When you upload a file to Send and share the link there is no way of knowing who or how many have downloaded the file. It would be useful if you could enable the option to either

  1. Log who downloaded the file (e.g. timestamp, IP, user agent, etc)
  2. Require people to submit name and/or email address before being allowed to download
  3. Both suggestions above