Top menu enhancements for workspaces

It would be nice to distinguish when a wiki is in virtual mode and when it is also the main wiki.

Additionally, in a workspace, to better display the hierarchy, it is useful to have a main wiki section in the top menu, different from the current workspace (subwiki) section that can be used to jump to the:

• main wiki homepage
• main wiki administration
• list of workspaces
• main wiki`s document index

In the workspace(wiki) section, an entry to delete the workspace.

Finally, add a Workspace entry in the 'Create' section and a 'Workspaces' entry in the user section.