* Rely not only on the FolderErrors event
* Request pull errors when opening the dialog
* Use "pullErrors" from FolderSummary
* Move code for directory error dialog into
its own class
This should fix that sometimes obsolete errors
were still displayed or actually present errors
missing.
It is a common error that dirs can not be removed
because they still contain ignored items. Usually
I want to get rid of them nevertheless. This change
allows to remove all non-empty Syncthing can not
remove via the tray.