Send appropriate requests to the server when dragging cards on project boards
Summary: Ref T1344. Makes requests to the server, which are received and ignored. Performs appropriate locking/unlocking/enabling/disabling on the client.
Test Plan: Dragged stuff around, saw it enable/disable/send correctly.
Reviewers: chad, btrahan
Reviewed By: btrahan
Maniphest Tasks: T1344
Differential Revision: https://secure.phabricator.com/D7943