Create a way to remove osmprj and perform self-updates

[travishathaway]

Description

Not providing users with a way to remove osmprj easily if they don't want it on their computer any more isn't very nice, and it's also really nice to be able to automatically update osmprj with a single command.

What should happen?

• Create a self-remove command that remove osmprj completely from a user's system
  • Ask if the user wants to remove cache folders
• Create a self-update command that can udpate omsprj to the latest version or any arbitrary version