IndependentVariable, not IndependentValue

--HG--
extra : amend_source : efe496419b391d3af10cf39bc81550fc8dd8fbf9
better setup for experiment.order API reference
fix See Also links
fix typos

--HG--
extra : amend_source : 07c82dffb56217e642783a2d83087be702ef719d
don't show class members
fix impossible-to-parse docstrings

--HG--
extra : amend_source : 492b99820c91f258659a9e2d2a9f5b699e92f240
use .dat file extension in examples