FolderWatcher: reliability and data-loss signal

Add state and signal to catch the following two known problems:
* Linux: inotify user watch pool is exhausted. Folder watcher becomes
unreliable.
* Windows: buffer is too small, some notifications are lost but watching
stays reliable.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gui/folderwatcher_win.h b/src/gui/folderwatcher_win.h
index 687ec891d..7ea673084 100644
--- a/src/gui/folderwatcher_win.h
+++ b/src/gui/folderwatcher_win.h
@@ -53,6 +53,7 @@ protected:
 
 signals:
     void changed(const QString &path);
+    void lostChanges();
 
 private:
     QString _path;