Reordering the projects listed on the main page to give a broader coverage, was currently dominated by cmgui/Zinc.

Zinc,Zinc plugin and Cmgui are all very close projects, it makes sense to just have one of them in the first 4, so that the first part of the list of projects gives a broader sense of the projects (depending on the browser window size, only the first one, two, three or four items from the list are displayed).