add numerical recipes library

lib/nr/ansi/recipes/arcsum.c

@@ -0,0 +1,18 @@
+
+void arcsum(unsigned long iin[], unsigned long iout[], unsigned long ja,
+	int nwk, unsigned long nrad, unsigned long nc)
+{
+	int j,karry=0;
+	unsigned long jtmp;
+
+	for (j=nwk;j>nc;j--) {
+		jtmp=ja;
+		ja /= nrad;
+		iout[j]=iin[j]+(jtmp-ja*nrad)+karry;
+		if (iout[j] >= nrad) {
+			iout[j] -= nrad;
+			karry=1;
+		} else karry=0;
+	}
+	iout[nc]=iin[nc]+ja+karry;
+}