dialogs api

[caisilus]

high-level api for dialog system

prot:

dialog = Dialog.new('my_dialog.txt', '2.txt')
dialog + dialog2
dialog.nodes => {}
dialog.validate => [errors]
dialog.characters
dialog.nodes['Приветствие'].characters => [Character]
dialog.nodes['Приветствие'].next => [Nodes]
dialog.nodes['Приветствие'].next 'Нет, я не хочу носить кольцо' => Node
dialog.start => starting Node