Add version number to root element of settings.xml

This will allow adding new functionality to existing settings.xml file without requiring users to do anything.

For example, when implement #35, would be able to add this new type. Then, existing installations would be able to use the new functionality

As part of this, add a Boolean to indicate whether the settings.xml should autoUpdate (defaults to true). This way, a user could always decide to not auto update even as new functionality was added.

Start by locating settings.xml and inspecting its current root element and how existing settings are read. Done means the root includes a version number and an autoUpdate Boolean that defaults to true, while allowing users to disable automatic updates.

Written by the indexing model from the issue text.