[Seaside] file path abstraction

[Rob Whitfield]

I have written an app that runs on a variety of platforms.  Is there an 
abstraction for specifying a sub folder that will work accross all 
operating systems?

For example, if I have a sub folder named "data" and I want to use 
FileStream to open foo.bar I would do this:

//windows
stream _ CrLfFileStream fileNamed: 'data\foo.bar'.

//unix
stream _ CrLfFileStream fileNamed: 'data/foo.bar'.

Must I detect the OS and use system specific folder naming conventions or 
does squeak have a more generic abstraction that would work in both cases 
using a single representation?