This test intermittently fails, likely because the auto-print is triggered fast enough
that we don't manage to get it.
So this patch aims to try to set a listener very early in order to be sure that
we'll be aware that a print has been triggered.
Some fields, somewhere under the Fields entry in Acroform, could have no name (in T)
but with a parent which has a name but which isn't somewhere under Fields.
As a side-effect, this patch prevents infinite loops because of potential cycles
under Fields.
