Keep track of files in playlist, even when their location on disk is changed

MacOS X provides a way for tracking files by a reference, known as an 'alias'. This means that once the user has selected a file, the program keeps hold of this reference, so if the user moves the file on disk, the link to the file is not lost. Adding this functionality to the playlist would be very useful, since currently (tested in 1.0.0-rc1) moving a file results in the corresponding playlist entry doing nothing when double-clicking.

Carbon provides this API:

http://developer.apple.com/documentation/Carbon/Reference/Alias_Manager/Reference/reference.html

Using this from Cocoa:

http://developer.apple.com/documentation/Cocoa/Conceptual/CarbonCocoaDoc/Articles/CarbonInCocoa.html#Using%20the%20FSRef%20Data%20Type

and then there is also this third party API:

http://www.cocoadev.com/index.pl?NDAlias

Note the referenced Carbon API will be available in Carbon 64-bit. See:

http://developer.apple.com/documentation/Carbon/Conceptual/Carbon64BitGuide/Introduction/Introduction.html