Move some aprhont/ stuff around a little bit

Summary:
"configuration/default" moved to "default". Rename it to "configuration" and put config stuff back there.

Put writeguard into writeguard/.

Test Plan: tools

Reviewers: vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T1103

Differential Revision: https://secure.phabricator.com/D2639