* configure.in: Comment out the --enable-newlib-fp-hw option
as the mathfp library is inaccurate and should not be used.
* Makefile.am: Add comment regarding the mathfp directory.
* configure: Regenerated.
* Makefile.in: Ditto.
* libm/mathfp/README: New file that details why the mathfp
directory is not used.