Comment 168 for bug 233901

Since the original document, I've learned enough c++ to read some of the pref loading code.

Changes:

1- added updated discussion about greprefs, application prefs.

TODO: extensions?

2- added updated list of application pref files, based on examining released versions on my Mac.

3- added further emphasis on about:config, by explaining localization features.

4- re-writing file changing sections to simply say how changing files affects the behavior. If you are a sys admin, a hacker, doing a distro, coding, etc, you get to figure out what files to hack yourself. This increases the learning curve for people who are just trying to hack *a* preference, and people hacking pref files.

(Also opens door for people interested in a specific app to write app-specific prefs docs....)

5- add discussion of hidden, default-less prefs.

I should update the file in the next few days... editing offline right now.