Eliminate eliminate_macros and fixpath.

These functions have been deprecated outside of MakeMaker for
many years, but due to the complicated inheritance situation
in EUMM have been difficult to get rid of because sometimes the
File::Spec versions would get called when we thought we were
calling the MakeMaker versions.  As of MakeMaker 7.04, the last
call to the File::Spec version of fixpath is gone, so we can
finally remove these from File::Spec.

And bump PathTools versions once again.