Closes #27

Closes #22

References #22

Closes #1

Supports selecting a match when more than one pattern may match for
regex and prefix matching.

The problem in Varnish issue #2880 comes about when len >= 49.

Closes #19

Thanks to @martin, @slink and @lf for their comments.

For sharding: we get the http port number from the Endpoints of the
Varnish service. From the PodSpec and -Status we get the host
name and the PodIP.

Initially to publish workqueue metrics.

Workaround for Varnish issue #2880:
https://github.com/varnishcache/varnish-cache/issues/2880

Refactor the test sources a bit while we're here.