Fixes #856

The test shows that using thwo proapgators work, but embedding them in a
propagator parallelizer does'nt work.

Fixes #862

The switch to new API is not complete yet, we still use instances of
AbstractJacobian, we just declare them as MatricesHarvesters.

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See merge request orekit/orekit!211

Fixes #847

JacobianColumnGenerator does not work yet. There is a scheduling
problem with StateTransitionMatrixGenerator because Hipparchus does not
have any ordering feature. AbstractIntegratedPropagator should probably
merge all objects registered using addIntegrableGenerator into one
single SecondaryODE presented to Hipparchus to work around this problem.