My computer had a power-down hissy-fit, and I've lost some of my IDEA setttings. (Before you ask, yes I wish my backups weren't broken at the moment, and I'm working on it...)
I'm pretty much certain I used to have tabs shown in multiple rows, and also in alpha order, but that doesn't seem to be an option. Searching the docs actually says that the way to enable aplha sorting is to show tabs in a single row.
Am I completely hallucinating here? Is there a hidden setting that does that? Is a plugin required?