Add Google+ to the web site template

[samueltardieu]

Icons for Google+ have been generated by @SammysHP for our web site.

The link should include the rel="publisher" attribute, as in:

<a href="https://plus.google.com/105588163414303246956" rel="publisher">…</a>

so that ownership of cgeo.org is linked to the Google+ account.

[Bananeweizen]

This request is about the website, right? Cause I was looking into adding an icon towards each of the links in the About -> Help page also. So it would be nice if we also had some matching icons for all those links (where I would prefer them to be in their normal colors, and not just black/white).

[samueltardieu]

Yes, it is for the website.

[SammysHP]

where I would prefer them to be in their normal colors, and not just black/white

https://www.google.com/search?site=&tbm=isch&q=icon+twitter+OR+google+

[Lineflyer]

Moved to cgeo/cgeo.github.io#19