* remove EIGEN_BUILD_TESTS and siblings
* add summary at the end of cmake run, hopefully not too verbose
* fix build of quaternion demo
* kill remnants of old binary library option
- quaternion vs euler angles interpolation (though the Euler angle version looks a bit too bad)
- navigation using either a mapping from 2D screen coordinates to 3D points on a sphere
or the standard approach mapping mouse displacements as rotations around camera's axes.