Re-introduced tempoary fix for singular matrix.
Support for kw VAPPARS.

When this kw is active, BlackoilPropsAdFromDeck now modifies rvSat
and rsSat curves cell-wise by a power of (sat_oil_cell /
sat_oil_cell_historical_max).   Currently, the associated jacobians do
not reflect terms of type d/d_sat_oil, but code for doing this is given
as comments to BlackoilPropsAdFromDeck::applyVap(ADB& r, ...).
Revert "Re-introduced tempoary fix for singular matrix."

Seems not to be needed any more ...
This reverts commit bb12bdd1fd8cdca7d39b7aa513a4a612b76451f8.
Bugfix, correcting incomplete merge.
Guard against "too small" max saturation.

This parameter might well be user configurable ...
Fixing some syntax.
Update of hysteresis model is now performed prior

to each time step, thus also capturing the initial state.
Merge pull request #163 from osae/vappars

kw VAPPARS etc