Added icon_48x48.ico so that pyinstaller/auto-py-to-exe can create a Windows executable with the actual NanoVNA-Saver project icon instead of a generic Python icon. The .ico was created by converting the icon_48x48.png image.
"Files" button in control panel changed to "Files ..." to be consistent with other "..." actions where a user will take additional action after pressing the button.
Minor corrections in the Calibration page "Are you sure?" and "Calibration assistant" pop-ups where text was being run together. e.g. "doso" instead of "do so" etc.
Fix issue: #663
* option --auto-connect, connect automatically to the 1st detected device
* autoconnect only if there is exactly one device
Signed-off-by: Martin <Ho-Ro@users.noreply.github.com>
t52ta6ek