v0.6.4

The script editor gives feedback at once and never opens blind.

Changed

• Script editor: the window opens at once and says it is reading the script, instead
  of nothing happening for seconds on a device with weak Wi-Fi. A second click or
  double-click does not open a second editor.

Fixed

• Script editor: when the device could not send the code (busy, HTTP error), an empty
  editor opened, and Upload would have wiped the script on the device. It now shows
  the error with Retry, and Upload / Upload and run stay off until the code was
  read. The API and MCP report the error too (Script.GetCode).