Replaced Flying image for Saved Map Vizes

Title pretty much says it all!  Addresses issue #1604

I chose the image from open clip art.  The choices were (sadly) few and far between.  The new saved map viz thumbnail on the index page is shown below:

![new_map_img](https://cloud.githubusercontent.com/assets/6451941/3635298/7d2dd1ac-0f69-11e4-8bdf-5cd6cb152f0b.png)