Scott Wallace <scott.wallace at squeakland.org>
announced updates to Squeak 3.4.
One of them puzzles me mightily:
	5131macRelativeFNFix-nk -- Ned Konz -- 23 November 2002
	The SARInstaller didn't work on the Connectors package because it 
	wasn't able to make the required subdirectories.
	This change set fixes the handling of relative and absolute filenames 
	under MacOS, and uses these conventions:
	* fileName starts with :: -> absolute
	* fileName starts with : -> relative
	* fileName starts with the name of a folder under the root -> absolute
	* otherwise -> relative
	It also fixes ArchiveViewer to use the previously-fixed extraction 
	code in ZipArchiveMember.
	
In MacOS, ::foo does not signify an absolute path,
but a path relative to the parent directory.
No other Macintosh programming language I've used
interprets multiple leading colons in a file name as absolute.

Why was this convention chosen?