Added vsqr(), vnf_centroid(), and vnf_volume()

vectors.scad

@@ -95,6 +95,14 @@ function vdiv(v1, v2) = [for (i = [0:1:len(v1)-1]) v1[i]/v2[i]];
 function vabs(v) = [for (x=v) abs(x)];
 
 
+// Function: vsqr()
+// Usage:
+//   x = vsqr(v);
+// Description:
+//   Returns a vector where each value in the original given vector is squared.
+function vsqr(v) = [for(i=v) i*i];
+
+
 // Function: unit()
 // Description:
 //   Returns unit length normalized version of vector v.