Add support for Local File System reserved directories

Mac OS X, and Windows has special purpose directories used to organizes specific types of files. In Mac OS X, these directories include "Documents", "Movies", "Pictures", "Music"; Windows uses "My Documents", "My Pictures", "My Videos" and "My Music".

Provide a consistent approach for getting these directories either as a static factory method, or as individual methods. i.e. something along the lines of "public static FileObject getRoot(int rootType)" where rootType is a constant that defines which one of the directorires (specified above) that you want.