Preserve import/export path in file dialogs

src/project.cpp

@@ -91,6 +91,7 @@ void Project::initSignals() {
 
 void Project::set_root(QString dir) {
     this->root = dir;
+    this->importExportPath = dir;
     this->parser.set_root(dir);
 }
 
@@ -2608,3 +2609,8 @@ int Project::getMaxObjectEvents()
 {
     return Project::max_object_events;
 }
+
+void Project::setImportExportPath(QString filename)
+{
+    this->importExportPath = QFileInfo(filename).absolutePath();
+}