New error message styles

* Add large red panel to summarise errors
- this looks like the green panels we use at the end of transactions,
with jump links
* Add a red outline to form fields, matching the width of the focus
style

![errors-mobile](https://cloud.githubusercontent.com/assets/417754/2997556/c28d6816-dd00-11e3-95e7-b0dee668ca85.png)
![errors-desktop](https://cloud.githubusercontent.com/assets/417754/2997558/caba83de-dd00-11e3-9738-fbddcac580d5.png)