Move version numbers to a dedicated "Versions" panel

Summary:
Currently, Version numbers are sort of randomly shown on "All Settings" beacuse we didn't have any better place to put them.

Now that we have modules, expose them as a config module.

Test Plan:

Grepped for "all settings" to look for other references to the old location, but didn't get any relevant hits.

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D14327