phobos: std.path enhancements

[SLI]

How about this enhancement for std.path:

new method:
char[] parent( char[] path, int up = 1 )
returns the parent path name of the given path, up indicates the levels for
"walking up", ´0´ would simply return the path parameter, ´1´ the parent, ..

extended method:
char[] join( char[] p1, char[] p2 )
it would be really nice if join() could also join "real" relative paths (p2)
such as "../sibling".

If helpfull I could provide the "authors" with a win specific implementation
e.g. to be used as a starting point.