Add feature: MultiCheckbox (checkboxes with multiple choices).

[RenoLooijmans]

[RenoLooijmans]

Hi Clint, thanks for your reply and sorry for my late answer. I'm happy to make these changes, though I'm interested in your internal version as well. If it's better I don't see why my pull request should be added back into the package :-)

I'm on holiday the next weeks, but I'll be sure to make these adjustments when I am back. Thanks again.

[ClintWinter]

The versions are very close other than the few comments I left, so I was trying to be nice and allow you to make a successful contribution rather than undercut you.

If you don't care, we can add the internal version instead, but you may end up making the adjustments before that happens 😆

Whichever comes first!