[META] 4.0 Beta3 Release Plan

Follow-up to #2425267: [META] 4.0 Beta2 Release Plan

This is going to serve as a meta issue for tracking the beta3 release of 4.0. I'm looking to take a more "agile" approach to this module and releasing versions on a bi-monthly basis. To start, I'm going to state 4.0-beta3 for July 1st. This ticket will track the tentative items to be fixed in that release.

Sprint board

Here is the sprint board for this release: http://contribkanban.com/#/board/1303302