ENH: Implement surface area in C

Calculates surface area in C. If module exposing the extension functionality cannot be loaded, or if it is disabled, python implementation is used instead.

radiomics/src/cshape.c

@@ -1,4 +1,3 @@
-#include <python.h>
 #include "cmatrices.h"
 #include <math.h>
 
@@ -218,11 +217,6 @@ double calculate_surfacearea(char *mask, int *size, double *spacing)
 int interpolate(double *vertEntry, int a1, int a2, double *spacing)
 {
 	int d;
-	/*int p1d[3];
-
-	p1d[0] = p1 / (size[1] * size[2]);
-	p1d[1] = (p1 % (size[2])) / size[1];
-	p1d[2] = p1 % (size[1] * size[2]);*/
 
 	for (d = 0; d < 3; d++)
 	{