Make Qube Manager remember its size from last time

Qube Manager will now remember its size from last time it was run, and
also it will no longer force itself to appear at top left corner of
the screen.

fixes QubesOS/qubes-issues#4049

qubesmanager/qube_manager.py

@@ -280,8 +280,6 @@ def __init__(self, qt_app, qubes_app, parent=None):
         self.frame_width = 0
         self.frame_height = 0
 
-        self.move(self.x(), 0)
-
         self.columns_actions = {
             self.columns_indices["Type"]: self.action_vm_type,
             self.columns_indices["Label"]: self.action_label,
@@ -405,6 +403,12 @@ def __init__(self, qt_app, qubes_app, parent=None):
         timer.start(1000 * 30) # 30s
         self.check_updates()
 
+    def closeEvent(self, event):
+        # pylint: disable=invalid-name
+        # save window size at close
+        self.manager_settings.setValue("window_size", self.size())
+        event.accept()
+
     def check_updates(self):
         for vm in self.qubes_app.domains:
             if vm.klass in {'TemplateVM', 'StandaloneVM'}:
@@ -525,6 +529,11 @@ def load_manager_settings(self):
         if not self.manager_settings.value("view/toolbar_visible",
                                            defaultValue=True):
             self.action_toolbar.setChecked(False)
+
+        # load last window size
+        self.resize(self.manager_settings.value("window_size",
+                                                QtCore.QSize(1100, 600)))
+
         self.settings_loaded = True
 
     def get_vms_list(self):