validation: remove unused files

index: redo form validation using rivets

register: redo form validation using rivets

contacts: use rivets more, don't spread model attributes

index: background color depends on bare jid since 96aec8cf1ae9

favicon: new ui element to display status (and incoming events in the future)

contacts: don't use 'presence' to determine pip color, use 'show'

index: improve onPresence() - default presence type is 'available', not 'online' - return early on all standard types that aren't currently handled - set default show and priority based on presence type - use status message in log - don't show status changes for contact type 'self'

contacts: fall back to bare jid for d/handle (to never show jid resource)

index: maintain only one contact with type 'self' This isn't done in an event handler of contacts collection because doing it in 'add' handler would trigger 'sort' event after the model has been added, but before its 'add' event has propagated, and that's dumb.