Refactor many project in order to isolate dependencies, especially from
``Log4Net'' and ``RDF'' libraries.
Finish to take apart dependencies in order for the ``Terranova'' dedicated
entry-point project to have only ``our'' libraries (those who start with ``it.unifi.dsi...'') and ``MathNet.Numerics'' library.
Add explicit reference to ``nunit.framework.dll'' in order to allow
compilation in Visual Studio too.
Removed an unnecessary reference to ``algebra'' project.