Test nested HTML pages

[rizo]

Attempts to fix #213.

I plan to split the work in two parts:

• Adapt the runner to diff multiple outputs per test case.
• Add, review and promote actual HTML files. (see comments below)

Maybe it's better to split the second point in multiple commits to make review easier.

[aantron]

Thanks, I'll take a close look tomorrow!

I recommend adding a minimum of extra files, i.e. omitting as much of the list in #213 as possible.

[aantron]

LGTM so far.

[aantron]

I suggest doing the second part as part of #261. We don't need to test every nested page. Many are generated as unneeded side effects of having dummy modules, for example. We just need to test nested pages in those tests where a useful feature is exercised, such as one page for #261.

[aantron]

(...which means I think this is ready for merge so that #261 can be rebased over it, let me know if you agree)

[rizo]

I agree @aantron, thanks for the review. Let's merge this and rebase #261.

I would suggest only closing #213 when we decide what other nested pages should be tested.

[aantron]

Thanks! #213 is still open after this merge.