[feature request] create capped box (collection)

[WhyPaulo]

It could be interesting to add a hard cap of maximum records inserted, also letting users specify a cap (if lower than the max setting).

[vasanthv]

I like this idea. But do you think users will set lower than the max count? Wont it be good if we set the limit?

Also, if we enable this feature https://github.com/vasanthv/jsonbox/issues/62 do you think we need max. records? Or do you prefer max records over auto deleting old records?