[detach-0.5.0] new formula for _detach_

Simple command line utility to run a command after detaching from the terminal.

Original author of the utility is Robbert Haarman (http://inglorion.net/). However, the site is not reponsive.

Current source pulls from a github mirror
The line here can be axed. The two ` end `s can rub heads & tails without issue.