Project "logo buttons" requested from iccubation process

[Jody Garnett]

As part of the incubation meeting today we discussed the impact OSGeo 
involvement should have on project websites.
In addition to eclipse.org which we reviewed, we went through the less 
structured apache.org

Until there here from us in more detail:
- logo button on the home page linking to osgeo.org
- logo button indicates project involvement

The buttons are up to us, we have options:
- use the logo and be minimal
- use the logo, foundation name, tag line
- provide a different button for projects in incubation

We should separate out the button for OSGeo projects vs web sites simply 
wanting to voice their support for us.

Cheers,
Jody