Hi. I want to suggest a couple of improvements for mongotop.

• count output in a grid view. Now only time is supported. Could be implemented with a command line flag
• limit the number of rows in a grid view with a command line flag (now 10 is hardcoded)
• pretty print of JSON (by flag)
• rename parameter rowcount to itercount
• date pretty print, something more human-readable than ISO format
• collect more granular stats from the top command. Now we only collect total and locks, * while we can insert, remove, update, etc.

I could implement them if the improvements are considered ok.