* testing operations continued
* algebra unit test included
* reorganizing tests
* changing algebra in order to work with boost.range
* resorganizing tests and regression tests
* finishing fusion_algebra test
* making the steppers copyconstructable
* making the controlled steper default constructable
* changing rel_error, should work now with boost::units
finished implementing support for units
* some refactoring, renaming names ....
* changing size_adjuster
* bringing implict_euler in shape
* cleaning header dependencies in test and regression_test
* moving error_checker_standard to controlled_error_stepper.hpp
* clean up and preparing the documentation
docs and dense output
dense output for dopri5
fixing constr correctness
* tutorial qbks
* dense output dopri5
* dense output dopri refactored
* some small file renaming
* doc ideas
* unit test stepper copying
* introducing stepper_with_ranges unit test
* small bug fixing in controlled_error_stepper
* dense output for units
* some refactoring
* testing explicit steppers with boost::range
* starting migration of rosenbrock
* introducing rosenbrock
* reorganizing