Add support for non-lazy classes and categories

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An alternative to #45 using NSMutableOrderedSet to avoid duplicates. Also, it doesn’t add an uint64_t address property on CDOCCategory and CDOCClass.

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ping

[nygard]

I'm looking at this now, but this change makes it miss a bunch of categories that it found before.

For example, Calendar on 10.10.3 has EKSource (EKSourceSidebarStubs). Keynote, MapKit, MoneyWell, Numbers, Pixelmator, Sketch, SoftwareUpdate are also affected.