Adds an option to show fully rectangular bounding box

[Basharath]

Hi Recently when I was using your bounding box library I wanted to have the bounding box be completely rectangular, unlike the square brackets. So I have added an option to show a complete rectangular bounding box without disturbing the actual bounding box.

Please have a look at it and let me know if it's fine.

Thank you.

[alx]

Hi @Basharath

Thanks for this pull request, it's great to have various display options for these boxes.

I'll have a look at your code and merge it as soon as possible.

Have a nice day,

Alex