Add ability to change project picture

Hi,

I propose a very small change that should be easy to make.

Currently on each of my projects I see myself smiling at me. While I do like myself, my picture on the project dashboard has little value.

Could you add the possibility to show there are custom picture?

Having that I could add a project picture (many projects have a logo). This would be useful to see directly in which of your projects you are.

Knut