#132 Modification to float.h

[Willus]

I'm not sure if I should be requesting this of the gcc folks or the MinGW team, but I have libraries / applications that want the following code in float.h, and I always have to add it after I install MinGW gcc. It would be nice if it could get put into the standard distro.

/* The difference between 1 and the least value greater than 1 that is
   representable in the given floating point type, b**1-p.  */
#undef FLT_EPSILON
#undef DBL_EPSILON
#undef LDBL_EPSILON
#define FLT_EPSILON    __FLT_EPSILON__
#define DBL_EPSILON    __DBL_EPSILON__
#define LDBL_EPSILON   __LDBL_EPSILON__