Multisite: Another fix. The last change made subdirectories work, but broke single post display. Now we can handle those, too.
Aaaaaand more multisite. This time we accidentally destroyed Habari installations with the core in a subdirectory. But now even multisite subsites with subdomain, core in a subdirectory and subsite in a subdirectory work (like something.habari.org/habari/en, where habari.org/habari is your base site). Yeah!