Don't obscure the save button when bulk editing lots of mappings

* When selecting many mappings users previously had to scroll a long way to the bottom to save their changes
* Instead hide mappings after the first 9, and show a link to reveal all of them

![screen shot 2014-02-26 at 16 26 12](https://f.cloud.github.com/assets/319055/2272213/bca5b764-9f02-11e3-8856-b690819daece.png)