Allow all data attributes

[nzgrover]

@parndt New PR to allow all "data-" attributes.

[bricesanchez]

/\Adata-[\w-]+\z/ Why do we hardcoded this regex and don't let the dev to be able to override it in a config?

[nzgrover]

@bricesanchez @parndt suggested he preferred this approach and asked me to submit a new pull request.

[parndt]

@nzgrover yes, I think what @bricesanchez is asking is whether we can move the regular expression itself to be configurable. I don't personally think we need to worry about that as it's easy enough for someone to write their own Presenter and Scrubber. Thanks for your work!

[sintro]

Hmm, looks like "render_content_page" method from '/refinery/content_page' template still removes the data-attributes.
Here is the fragment of log warning after sanitizing:

<div class="image">
-        <img width="300" height="65" alt="Slide Background 2" title="title1" data-no-retina="true" src="/system/images/image.jpg" />
+        <img width="300" height="65" alt="Slide Background 2" title="title1" src="/system/image/image.jpg">
</div>

As one can see here, Scrubber has removed the 'data-no-retina' attruibute.

PS
I do have lines

def scrub_attributes(node)
  node.attribute_nodes.each do |attr_node|
    next if attr_node.node_name =~ /\Adata-[\w-]+\z/

    super
  end
end

in my section_presenter.rb