Huge engine change, replace all std::shared_ptrs

Create a new shared pointer type stdext::shared_object_ptr and stdext::shared_obj
using boost::intrusive_ptr

Advantages:
 * half memory usage
 * faster and lightweight

Disadvantages:
 * using weak_ptr is not supported anymore
 * compiling seems slower

src/framework/graphics/shader.h

@@ -25,7 +25,7 @@
 
 #include "declarations.h"
 
-class Shader
+class Shader : public stdext::shared_object
 {
 public:
     enum ShaderType {