Fixes bug 1052368 - Added a deprecation notice to Advanced Search.

@KaiRo-at f?
@phrawzty r?

Here's what it looks like:

![advanced-search-deprecation](https://cloud.githubusercontent.com/assets/328790/4767656/66be307c-5b60-11e4-9c85-30f34b54c51b.png)

What @phrawzty said.