more e2e tests for node & rnode proxies.

[johrstrom]

Given #3728 and #3776 we should add more e2e tests for /node and /rnode URIs to ensure they're being correctly routed. In fact the e2e tests showed that httpd was broken at all in #3728.

In any case, let's add to these tests so that we test for

• query parameter parsing

That's about all I can think of off the top - but could be more by the time I get around to implementing it.