VE-456: Accesskeys based on editor preference

https://wikia-inc.atlassian.net/browse/VE-456
So I was thinking... @mklucsarits told me that accesskey can be passed among text, class, href into $links configuration (look at onSkinTemplateNavigation in EditorPreferences)... so it could assign "s", and "e" properly... Then, undoing change (in case of not supported browser) could be handled in removeVELink. That way we keep low amount of places which do something to those links.