The behat 'I wait "x" seconds' step unnecessarily requires JS

At the moment this step passes straight to the getSession()->wait(), which waits for x-thousand milliseconds and then runs a piece of JS. This meanst hat if you need to wait, you need JS.

This step is used in several places to wait for a timeout to expire (e.g. badges + forum maxedit time). In these cases, not only are we waiting for 61+ seconds, we're also requiring JS in order to do so.

We should have a non-JS fallback of using PHP sleep instead.