[docs] [issue29688] Add support for Path.absolute()

INADA Naoki added the comment:

posixpath.abspath() collapses "<path>/<symlink>/.." to "<path>", this is not correct. Not sure about ntpath.abspath().

I feel this is reasonable limitation, and expected behavior for some cases. So I think adding note about this in document is enough. ---------- nosy: +inada.naoki _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue29688> _______________________________________