NAME
    AddPart -- Appends a file/dir to the end of a path (V36)

SYNOPSIS
    success = AddPart( dirname, filename, size )
    D0                   D1        D2      D3

    BOOL AddPart( STRPTR, STRPTR, ULONG )

FUNCTION
    This function adds a file, directory, or subpath name to a directory
    path name taking into account any required separator characters.  If
    filename is a fully-qualified path it will totally replace the current
    value of dirname.

INPUTS
    dirname  - the path to add a file/directory name to.
    filename - the filename or directory name to add.  May be a relative
               pathname from the current directory (example: foo/bar).
               Can deal with leading '/'(s), indicating one directory up
               per '/', or with a ':', indicating it's relative to the
               root of the appropriate volume.
    size     - size in bytes of the space allocated for dirname.  Must
               not be 0.

RESULT
    success - non-zero for ok, FALSE if the buffer would have overflowed.
              If an overflow would have occured, dirname will not be
              changed.

BUGS
    Doesn't check if a subpath is legal (i.e. doesn't check for ':'s) and
    doesn't handle leading '/'s in 2.0 through 2.02 (V36).  V37 fixes
    this, allowing filename to be any path, including absolute.

SEE ALSO
    Filepart(), pathpart()