Add support for -loop and -every to collect data on regular basis

[colinpaicemq]

Ive added some change to allow -count n and -every n to allow the data to be queries continually, and so extract data and then a spread sheet showing chart of usage over time. I can see no other way of getting statistics charts out of web servers. I would like to be able to chart information over a week, with data done every half hour, and piped to down stream processing, The data has date and time information

I've also fixed a bug where no value causes an infinite loop. It now reports "Missing"