URL Shortener links for hackaday.io.

• Link message boards
  • http://hac.io/m/2369 goes to  https://hackaday.io/messages/room/2369
• Link to projects
  • http://hac.io/o/399 goes to https://hackaday.io/project/399
• Link to users
  • http://hac.io/u/daren goes to https://hackaday.io/daren

For users, you need to use the username instead of the user number, which may or may not be shorter than just https://hackaday.io/hacker/2335