Add DISABLE_CLASS_COPY macro (and use it)

Use this macro to disallow copying of an object using the assignment
operator or copy constructor.  This catches otherwise silent-but-deadly
mistakes such as "ServerMap map = env->getMap();" at compile time.

If so desired, it is still possible to copy a class, but it now requires
an explicit call to memcpy or std::copy.

src/map.h

@@ -365,6 +365,8 @@ private:
 	u32 m_unprocessed_count;
 	u32 m_inc_trending_up_start_time; // milliseconds
 	bool m_queue_size_timer_started;
+
+	DISABLE_CLASS_COPY(Map);
 };
 
 /*