Ubuntu 12.04 run a custom command on CD / DVD insertion (EAC and audio CD)

In Ubuntu 12.04 the option to run a custom command on the insertion of removable media has disappeared (this is a very frustrating regression!). Previously I had a custom shell script that would intelligently automate the ripping of audio CD to FLAC, ALAC and MP3 using EAC. This script had become redundant due to the missing option of running custom commands on CD insertion. Here's how I now run a custom command on audio CD detection in Ubuntu 12.04...