There was some code to attempt to display the error in the right
pane, whenever it occured in the app early phase.
However, it made it much harder to properly handle all cases. It could
silently swallow some errors (if more than one was done), And it was
not behaving the same way in Firefox and in Chrome.
We don't see any usecase for it, it makes the code more complex,
and there were still potential unresolved concurrency issues with
it.
Part of task #295
Géry Debongnie