Open links in popup window

:rotating_light: :construction: WIP :construction: :rotating_light:

My experience with share icons is that they open the share module in a popup window, as they are not typically designed to function well on a large canvas. In this implementation the popup is forced for all links except mailto: links. The popup is forced to 500px square, as I'm not sure what the optimum size would be.

Ideally this would be a config option for users to set when adding this to their site, but I did not see any of those already. I'm not sure if this would add extra setup complexity that you would want to avoid.

On mobile this opens the share page in a new tab, I prefer this as it doesn't force users away from the page they are on, and once they are done sharing they can close that tab and return to where they were

**Known Bugs**
There is a delay from when I click on the link to when the popup opens, I'm not exactly sure what is causing that.

Is this something that you would be interested in adding?