Recommendations for SPARQLES improvements

[cbuil]

These things could make my experience better:

• I don't fully understand the "availability" graph, i.e. why it doesn't add up to 100%.
  Perhaps it can be made clearer—and could it also be made up-to-date?
• Could the availability / performance / … pages be sortable?
• When I click a particular endpoint, I reach its status page.
  (i.e. http://sparqles.okfn.org/endpoint?uri=http%3A%2F%2Fwww.rdfabout.com%2Fsparql)
  On that status page, it would be nice if I could click through the actual endpoint.
• Maybe basic statistics on an endpoint, when available, would be interesting (triple count etc.).

[aidhog]

This should be split into multiple issues I think. For example, the availability graph has probably been resolved (though it's not ratio based, but absolute number based). The rest are feature requests.