Initial implementation of a music player for the jukebox.rb front-end, written in Objective-C using Cocoa libraries for the Mac.

This project has some outstanding issues that need to be addressed:
 - probably not using Objective-C conventions for some things, performing unnecessary nil checks, and things of that nature.
 - unsure of memory management best practices.  as far as I can tell, the app doesn't leak, but some of the statements in the app seem redundant, and/or they might not all be in the right places.
- needs lots of unit tests, build scripts, and possibly installers.

Usage:
- launch the jukebox.rb web site using script/server from that project's root directory.
- execute the binary generated by this project.  it will communicate with jukebox.rb via a restful interface and play music from the local hard drive (ie, both jukebox.rb and this player need to be running on the same machine).

This is a work in progress and there may be undiscovered issues.  Assistance in addressing the outstanding issues is welcome and appreciated.