Feature/typedef using refactoring

another set of massive refactoring:

• typedef replaced by using
• using removal at the header level
• no more using namespace nsx at the nsxqt level
• untemplated overtemplated classes (Ishape interface + concrete child classes, ConvexHull, NDTree)
• unused files removed
• files renamed
• many warnings removed (still many left yet)
• replaced explicit {shared,unique,weak}_ptr instantiation by auto
• remove using boost::.. and replaced by fully qualified declaration instead