sonar-click only works for links

I don't know if this issue is fixable via CSS, at the moment `sonar-click` uses the `:focus` selector to trigger when an element is clicked, which only works on "focusable" elements, like links, inputs...

Replication: http://jsfiddle.net/2ywv1ze9/1/

If anyone has any ideas for this it would be awesome.

Start by reproducing the behavior in the linked JSFiddle and inspect how `sonar-click` uses the `:focus` selector. Determine whether a CSS-only approach can trigger the effect on non-focusable elements; done means the effect works for the reported element types without breaking links or inputs.

Written by the indexing model from the issue text.