moved doc/examples to examples according to new build process

examples/smartpointer.cxx

@@ -0,0 +1,26 @@
+#include <mrw/smartpointer.hxx>
+
+class A {
+  public: int a;
+  public: virtual ~A() {}
+  protected: virtual void fn() {} // dynamic_cast requires a virtual function
+};
+
+class B: virtual public A {
+  public: int b;
+};
+
+int main(int, char**) {
+  mrw::SmartPointer<int> i1 = new int;
+  *i1 = 13;
+  mrw::SmartPointer<int> i2 = i1;
+  mrw::SmartPointer<int> i3;
+  if (!i3) i3 = i2;
+  *i2 = 666;			// *i1 is now 666 too
+  mrw::SmartPointer<A> b1 = new B;
+  mrw::SmartPointer<B> b2 = b1; // b1 and b2 point to the same instance
+  b1->a = 0;			// b1->b does not compile
+  b2->a = 1;
+  b2->b = 2;
+  return 0;
+} // memory is automatically freed