Fix broken ifdef, not sure why it was breaking it

Probably some historical reasons. When like this, it works with current GCC

threeDKit/quickmath.h

@@ -60,7 +60,7 @@ typedef struct {
 #define max(x,y)     (((x) > (y)) ? (x) : (y))
 #define min(x,y)     (((x) < (y)) ? (x) : (y))
 
-#ifndef __GNUC__
+#ifdef __GNUC__
 
 double fsqr (double x);
 int lsqr (int x);

utils/gtf/gtfcalc.c

@@ -64,7 +64,7 @@ static GTF_constants GC = {
 
 /*-------------------------- Implementation -------------------------------*/
 
-static double round(double v)
+double round(double v)
 {
 	return floor(v + 0.5);
 }