The reference value used for the test is updated for the following
reasons:

1/ No reference for the origin of value used in the test
2/ The fixed issue is consistent with IERS 2010 equations

Fixes #799

Fixes #821

Fixes #819

Fixes #814

Thanks to Sam for the report!

They have been replaced by a versatile step handler multiplexer
fulfilling all these needs simultaneously during a single
propagation run.

Fixes #809

Fixes #812