Suggestion for metrics load performance

[engFelipeMonteiro]

I suggest that the generate_latest function that itarete over all metrics and sample, every request. Could be replaced for a way to generate a static page, or as contatenate strings(metrics).

To accomplish this when generating the data for metrics on the end of each, it converts the metrics to it's respective string.

With this we can have a semi-static page, for faster loading.