[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 #62 do you think we need max. records? Or do you prefer max records over auto deleting old records?