Bootstrap is beloved by many. Well, if not “beloved”, then it is at least appreciated for what it is: a giant framework with almost everything you could need for building a site or web app interface. Bootstrap is changing, though. That’s right, version four is in alpha release. Naturally, we're just as curious to know what’s different, so I dived into the documentation to find out. Keep in mind, though, that this is an alpha release. It cannot be considered feature-complete. It could radically...