preventing SVGs in IE/Edge from receiving tab focus

[dlockhart]

This fixes #46 by setting the focusable attribute on the SVG to false, which prevents SVG elements from receiving tab focus as the user tabs around the page in IE and Edge.

Information on the focusable attribute from the SVG W3C spec: https://www.w3.org/TR/SVGTiny12/interact.html#focusable-attr

Stack Overflow discussion of this fix: http://stackoverflow.com/questions/18646111/disable-onfocus-event-for-svg-element

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[dlockhart]

I signed it!

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CLAs look good, thanks!

[AlvaroGonzalezCans]

Hello, what is the state of this merge request?

[bicknellr]

:+1:

[bicknellr]

Hey, @notwaldorf just pointed out to me that you (or someone else watching this thread) might need this in 1.x, as the PR is from quite a while ago. If so, feel free to open a copy of this PR with 1.x as the base branch and I'll merge it there as well.

[dlockhart]

@bicknellr & @notwaldorf thanks for thinking about that! Not needed, as I've got a workaround in place inside one of our components that I'll keep around in the Polymer 1.x version of that component and remove when we make the jump to 2.x. Thanks though!

[ghost]

Hey @bicknellr, thanks for fixing this issue. I created a pull request for the 1.x branch, please merge it as well: https://github.com/PolymerElements/iron-iconset-svg/pull/73