GSL for MS Visual C++

[Brian Gough]

Anthony RABINE writes:
 > error C2201: 'gsl_prec_eps' : must have external linkage in order to be exported/imported
 > error C2734: 'gsl_prec_eps' : const object must be initialized if not extern
 > error C2133: 'gsl_prec_eps' : unknown size

Thanks for the bug reports.  I'll look at this problem again when I
make the MSVC version of gsl-1.3.

-- 
Brian Gough