It should be configurable whether this happens -- an admin may want
to intentionally stop Varnish, and this feature would interfere with
that.

Get some mod tidy done while we're here.

In case Pod names ever change without changing endpoint addresses.

We don't need a binary-to-text encoding for the hash, we just test
the binary result. We also don't need to sort []Endpoint or hash
Service.

InitTemplates() takes a map of template paths to file paths, and
returns a map of parsed template to file paths.

Add WriteTemplate(), which takes a parsed template and a file path,
and generates VCL at the path from a spec and the template. Meant
for iteration on the map returned by InitTemplates().