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/animatedtexture.cpp

@@ -70,7 +70,7 @@ void AnimatedTexture::processAnimation()
     AnimatedTexturePtr self = asAnimatedTexture();
 
     // continue to animate only if something still referencing this texture
-    if(self.use_count() > 1)
+    if(self->ref_count() > 1)
         g_dispatcher.scheduleEvent(std::bind(&AnimatedTexture::processAnimation, self), m_framesDelay[m_currentFrame]);
 }
 */