* 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
1) Eigen2 co-installable with Eigen1 without conflict, without affecting programs including either.
2) #include<Eigen/Core> without the .h without conflict with the Core/ directory
3) Uniformize coding style of the CMakeLists.