Run ODE tests now with upwinding options of FV and DG solver
where a change of the residual tolerance limit was not necessary.

Several adjustments were made to make applying local operator options
easier:
* Remove 'EXPERIMENTAL_DG_FEATURES' option. Settings in config file
  now apply by default.
* Move previously experimental options to 'richards.numerics' section.
* Rename settings 'method' to 'DGMethod' and 'weights' to 'DGWeights'.
* Fix typo: Rename OOB to OBB scheme (Oden, Babuska, Baumann).