Simple but required additions (no mixed/conflicting changes)

[BhagyaJyoti22006]

1. Added codes to allow changing value for radiobutton via .configure
2. Added codes to define font for the buttons used in tabview widget
3. Added master parameter for PhotoImage object in ctkimage to fix garbage collection error
4. Added codes to get and modify the font of button used in tabview widget

I have ensured that there are no short cuts made in these changes. I think Tom would have also achieved these things like I have done. Unless I missed something over my head.