Option to open links in a new tab/window

[aschweigert]

@JamesPoundCSJ said:

It would be great to have the option to open links in a new tab/window, especially since they go off-site.

See conversation on https://github.com/INN/argo-links/issues/22, but tl;dr: this could be an option in the plugin settings with the default set to NOT open in a new window because that's generally a better user experience.

[benlk]

If we do this, it should be rel noopener noreferer: https://www.jitbit.com/alexblog/256-targetblank---the-most-underestimated-vulnerability-ever/

[benlk]

Moving this to the 0.5 milestone because it turns out that we do have this option in the Saved Links widget.

[benlk]

With #162 merged, affecting the saved links widget, the issue of getting links in roundups to open in new tabs can be addressed in a later version.
Perhaps we can write docs for sites to change their own default link display HTML?