Convert global settings to list subclass

The style is unclear and inconsistent about whether the settings are preferred to be lists or tuples. A discussion in the mailing list seems to indicate a consensus that lists are preferred, but backward compatibility _may_ be a concern that needs to be considered.

I've implemented a `ConfList` list subclass that is able to act like a tuple in some tricky cases that might otherwise throw errors. Based on recent posts on the mailing list, the `ConfList` subclass is likely to be discarded in favor of simply documenting the backward incompatibility.

I updated the default template to use lists, and I've started working my way through the tutorial, and then on to the rest of the docs. There's still a bunch more to go through.