Add Ctrl-Q/Command-Q to quit (#12)

* add menu with quit
* add comment
* don't add unnecessary File menu for macos

Author: benjamink

esphomeflasher/gui.py

@@ -190,6 +190,16 @@ class MainFrame(wx.Frame):
     def __init__(self, parent, title):
         wx.Frame.__init__(self, parent, -1, title, style=wx.DEFAULT_FRAME_STYLE | wx.NO_FULL_REPAINT_ON_RESIZE)
 
+        # Add menu with quit option
+        menubar = wx.MenuBar()
+        file_menu = wx.Menu()
+        quit_item = file_menu.Append(
+            wx.ID_EXIT, "Quit\tCtrl-Q" if sys.platform != "darwin" else "Quit\tCmd-Q", "Quit FujiNet-Flasher")
+        if sys.platform != "darwin":
+            menubar.Append(file_menu, "&File")
+        self.SetMenuBar(menubar)
+        self.Bind(wx.EVT_MENU, self._on_exit_app, quit_item)
+
         self._firmware = None
         self._port = None
         self._upload_baud_rate = 460800