R1:851d02b30a0f

Define STATUS_MOVED constant ahead of its implementation

Summary: I landed some patches out of order and we haven't landed the one which actually implements this yet. Define the constant for now.

Test Plan: Deleted a page in Phriction without issue.

Reviewers: AnhNhan

Reviewed By: AnhNhan

CC: aran

Differential Revision: https://secure.phabricator.com/D5207