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.World/CommandDispatcher.h

@@ -14,6 +14,6 @@ private:
 	unordered_set<Command *> commands;
 
 public:
-	void performCommand(shared_ptr<CommandSender> sender, EGameCommand command, byteArray commandData);
+	void performCommand(std::shared_ptr<CommandSender> sender, EGameCommand command, byteArray commandData);
 	Command *addCommand(Command *command);
 };