[Bug-gnubg] MET interpolation algorithm

[Holger]

Hi all,

gnubg (GUI) segfaulted when showing the MET right after startup with the
new mec table. It did this whenever it should show interpolated values for
this MET.

I've put in a hack that should avoid gnubg crashing. But the interpolation
algorithm seems to be faulty. Look at the post-crawford values for player 0
for more than 24-away.

Regards,

        Holger