LEWorkViewController

## LETalk

* Add plaintext body property

## LETalkViewController

* Reflect changes to LEWorkViewController

## LEWorkViewController

* Now a subclass of UITabBarController
* Change generic detailItem to specific LETalk

## Objective-C Magic

* Split configuration paths for the editor, according to the type of
the selectedViewController

## Style

* Use the Oxford semicolon after method declarations.
Fix a crasher in NSAttributedStringMarkdownParser
## LEWorkViewController

* Now a tabbed view that shows the selected talk in several views.
* Eventually this will be preview and edit modes
* For now we have several preview modes so we can compare them.
## LETalkViewController

* Remove the reference to the work controller.
* Rename the seque to the work controller “SelectTalk” as it may include issues as well as comments.
* Assert that the destination controller is a LEWorkViewController

## LEWorkViewController

* Retrieve the body view by tag rather than assuming it’s the only subview
* Become the UITabBarControllerDelegate

### Bugs

* It seems viewDidLoad is too soon to configure the view, but that’s OK because it’s configured when the selected view changes.
* However, the selected view does not change when the controller is loaded for the first time.
* Configure work view on viewDidAppear: so it has content when the view first loads.
* Move a comment into a TODO for future experience polish.
* Fix some layout issues to keep the various text views in bounds.