[Ifeffit] Bugs in Athena under Windows

[Timna-Josua Kuehn]

Hello,

since the last two versions of Athena under Windows some serious bugs have 
appeared. Whenever I merge some datasets, Athena somehow breaks down 
afterwards. The window is still open, but I can not plot anything, nor do any 
other operation. The same happens when I try to align or convolute some 
spectrum.

Thanks for checking this.

Timna