R1:3fdaf229a70f

Convert Create/Edit Column pages to dialogs

Summary: Makes these pages a dialog endpoint, keeping you on the Workboard when possible.

Test Plan: Create a Column, Edit a Column, visit hard page. Test letters in the points field.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15270