Finds the directories of Absolute by walking up the absolute path
until it reaches the root. Operates on paths only; it does not check
that Absolute actually exists. Absolute can be a directory or file
Fails if Absolute is not an absolute file name, according to
is_absolute_file_name/2. Works correctly for Unix and Windows paths.
However, it finally unifies with the drive letter under Windows, and
the root directory (/) on Unix.
|Absolute||- specifies an absolute path name. On Windows it must
typically include a driver letter, else not absolute in the complete
sense under Microsoft Windows since its file system supports
multiple root directories on different mounted drives.|