Collect at every scrape, rather than at regular intervals.

Switch to Update using the Collecter Collect interface, due to not knowing all
metricnames in all modules beforehand we can't use Describe and thus the full
Collecter interface.

Remove 'updates', it's meaning varies by module and doesn't add much.
Merge pull request #24 from brian-brazil/master

Collect at every scrape, rather than at regular intervals.