* rebase editorial workflow pull requests when behind
* fix async/await transpilation
* add media library pagination
* switch media library to grid layout
* ensure that only cms branches can be force updated
- New state field: `state.entryDraft.hasChanged`, initialized to
`false`.
- `state.entryDraft.hasChanged` set to `true` in `entryDraft` reducer
for `DRAFT_CHANGE_FIELD`.
- `EntryPage` adds a `listenBefore` listener to `history` on
`componentDidMount` that checks `this.props.entryDraft.hasChanged`
and, if that is true, asks the user to confirm the navigation.
- `EntryPage` removes its listener on `componentWillUnmount`.
* Field config options: 'required' and 'pattern'
* Widget controls can implement it's own isValid
* Validation errors store in redux & displayed
* Support for returned Promises in isValid
* Allow widget controls to return either a boolean, an error object or a promise from isValid
* Add metadata to draft entry fields
* Do not render widget if value is null
* Pass along metadata
* Namespace queries to avoid conflict
* Query relational field on mount (for when editing entries)
* Make sure metadata is Immutable
* Added collection name as metadata keys
