Remove more insignificant differences with examples in master

Follow the she style of the other existing examples.

Examples/c/class/example.cxx

@@ -1,4 +1,4 @@
-/* File : example.c */
+/* File : example.cxx */
 
 #include "example.h"
 #define M_PI 3.14159265358979323846
@@ -11,18 +11,18 @@ void Shape::move(double dx, double dy) {
 
 int Shape::nshapes = 0;
 
-double Circle::area(void) {
+double Circle::area() {
   return M_PI*radius*radius;
 }
 
-double Circle::perimeter(void) {
+double Circle::perimeter() {
   return 2*M_PI*radius;
 }
 
-double Square::area(void) {
+double Square::area() {
   return width*width;
 }
 
-double Square::perimeter(void) {
+double Square::perimeter() {
   return 4*width;
 }

Examples/c/class/example.i

@@ -7,4 +7,3 @@
 
 /* Let's just grab the original header file here */
 %include "example.h"
-

Examples/c/exception/example.h

@@ -1,5 +1,6 @@
 /* File : example.h */
 
+#include <string.h>
 #ifndef SWIG
 struct A {
 };
@@ -10,7 +11,7 @@ class Exc {
 public:
   Exc(int c, const char *m) {
     code = c;
-    strncpy(msg,m,256);
+    strncpy(msg,m,255);
   }
   int code;
   char msg[256];