Merge pull request #2959 from wenqing/cp_reg_van_genuchten

...anGenuchten/c_CapillaryPressureRegularizedVanGenuchten.md

...ty/CapillaryPressureRegularizedVanGenuchten/t_exponent.md

...roperty/CapillaryPressureRegularizedVanGenuchten/t_p_b.md

...ssureRegularizedVanGenuchten/t_residual_gas_saturation.md

...reRegularizedVanGenuchten/t_residual_liquid_saturation.md

Documentation/bibliography.bib

MaterialLib/MPL/CreateProperty.cpp

...reSaturation/CapillaryPressureRegularizedVanGenuchten.cpp

...sureSaturation/CapillaryPressureRegularizedVanGenuchten.h

...ration/CreateCapillaryPressureRegularizedVanGenuchten.cpp

...turation/CreateCapillaryPressureRegularizedVanGenuchten.h

MaterialLib/MPL/Properties/CreateProperties.h

MaterialLib/MPL/Utils/CheckVanGenuchtenExponentRange.cpp

MaterialLib/MPL/Utils/CheckVanGenuchtenExponentRange.h

...alLib/TestMPLCapillaryPressureRegularizedVanGenuchten.cpp