Remove 'WiktionaryConnection', use Api instead
Move GUI handlers into Presentation
Move into folders, cleanup; begin splitting MainWindow/EditController

Files moved into folders BusinessLogic, DataAccess, Presentation and Core.
Add icon
Indicate error when giving bad 'max entries' number
Make Page handle edit summary
Distribute responsibility between EditController and TranslationEditor

EditController retrieves list of articles, sends them out for changing
and saves them if needed.

TranslationEditor *only* modifies the wikitext when needed.
Move delegate callbacks to EditController, where they are used
Move page formatting into its own class
Merge branch 'restructure'