shared_ptr -> std::shared_ptr

This is one of the first commits in a plan to remove all `using namespace std;` lines in the entire codebase as it is considered anti-pattern today.

Minecraft.Client/InventoryScreen.h

@@ -6,7 +6,7 @@ class Button;
 class InventoryScreen : public AbstractContainerScreen
 {
 public:
-	InventoryScreen(shared_ptr<Player> player);
+	InventoryScreen(std::shared_ptr<Player> player);
     virtual void init();
 protected:
 	virtual void renderLabels();