Tomorrow’s tagging, today.

This adds support for Mavericks' tagging to the Finder plug-in. It was adapted from the OpenMeta plug-in (with permission) since the systems are nearly identical.

I said earlier that it would work under 10.7 and 10.8, but that turns out to be wrong. There's an underscore in the attribute name that Spotlight doesn't parse correctly in those versions. It works great under 10.9, though.

Just one issue to resolve: There's a warning about the NIB that makes no sense to me. I've been through the Attributes and Size inspectors and don't see any way to change what it's complaining about.
  
> /Users/rob/Coding/Quicksilver/Quicksilver/Quicksilver/PlugIns-Main/Finder/Resources/QSTaggedFilesSource.xib:9: Use Current Width For Max Layout Width on Mac OS X versions prior to 10.8