We need a function to walk a directory and replace absolute symlinks with
relative ones. Add such a function to the path module of lib/oe.
It does this relative to the directory being walked for files.
(From OE-Core rev: 15376e5ff35367c1b40941d10e7b19302058a53e)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>