Something releated to AMD broke our way of injecting Sizzle into Galaxy for Selenium tests. This is a much better way that seems to work - just use jQuery ($) as Sizzle if it is available. Avoids an external dependency and another page fetch per test as well as fixing the problem.
Add a test case that just tests the sizzle stuff works on its own. It will be a clear indiciation what is broken if there are related regressions in the future.
