We should enumerate the components directory only once (_possibly_ more if we're doing initial autoregistration, but maybe the installer should have to worry about that), dispatching to prefs and the typelib loader and whatnot based on file suffix.

The current list of places in the codebase that do enumeration of the components directory are: - autoregistration = nsNativeComponentLoader.cpp = mozJSComponentLoader.cpp - default pref loading = nsPref.cpp - typelib file loading = nsInterfaceInfoManager.cpp Coming soon, I think: - chrome fragment registry Question for Simon: how do we dispatch on the Mac? Do we require use of file suffixes, or do I need to map from file type to ``virtual suffix''? Question for the crowd: do we care about making autoregistration participate in this? It'd be a lot of work to get the ordering work, and I want autoregistration to die anyway. If we don't, we still reduce the number of directory iterations by one and can probably make that iteration faster.

Pref no longer enumerats components directory. Neeti fixed that one.

This appears not to matter.