Pull latest dev changes into bootstrap3

Here are some recent changes to dev, that should be merged across into the bootstrap3 branch. We'll want to make sure there's nothing here that breaks in b3 (but I don't think there will be, or if there is, it'll be a few minor view tweaks; there's no serious front-end work on dev at present).
This is the only non-whitespace change to the CSS. We need to make sure this, or its moral equivalent, comes across to the bootstrap3 branch.