Get rid of all the unused stuff.
internally use Eigen for computing Inverse.
Removed the stupid incomprehensible method Invert() that changed the matrix itself.
Nobody was using it in a reasonable way.
* update the gl/math wrappers to make them more Eigen friendly
(and remove the useless, and not used, and somehow dangerous
*Direct and *E functions)
* add automatic reinterpret_casting from Eigen::Matrix to vcg
specialized types
* curently nothing change if you don't define VCG_USE_EIGEN
* make Matrix*, Point3 and Point4 derive Eigen::Matrix (still ugly)
* now catching all the dot products to replace them by .dot()
note that most of meshlab already compile
Paolo Cignoni
mtarini
granzuglia