created a view to display and to edit group description article. This ar...

created a view to display and to edit groups description articles. This article is a subpage of the home article. I also created 2 templates extending workgroup_detail and wiki_edit accordingly. Modified a bit wiki_edit and workgroup detail to be able to override the edit links. altered a bit workgroup_header to display the description tab.
TODO: bit of integration for the "description" tab to display properly