(instead of dispatching `load` event to merge them into `history`)
This is cleaner becuase now `context` doesn't need to keep an
`altGraph` state used only for Conflict Resolution.
The conflict resolution code calls the `iD.Connection` methods directly,
and other places in the code call `loadEntity` and `loadTiles` wrappers
that merge the entities into the main history.
Because the embedded iD does not show the account
UI, Connection#userDetails was not being called, so
the commit UI didn't show the user name and image.
Fixes#1464
