DOMNodeComparator swallows comments

[theseer]

In DOMNodeComparator::nodeToText we call $node->C14n(); without any parameters.

That results in all Comment (<!-- ... -->) nodes to be stripped.

I'd consider that a bug.

Given we still have #87, and maybe #71, we should probably have a look into how this comparator works :)

[theseer]

Additionally, the DOMNodeComparator::nodeToText has a bool parameter $canonicalize suggesting it could be optional. But the only caller, DOMNodeComparator::assertEquals, hardcodes it to true in both cases.

I guess we really need to refactor this one :)

[theseer]

Maybe we can use some of PR #88 while doing so.

[WinterSilence]

@theseer #97