merging oilcrops and pulses into one commodity type

GAMS/LUOpt.gms

data/DemandParameters.gdx

src/ac/ed/lurg/ModelConfig.java

src/ac/ed/lurg/country/AbstractCountryAgent.java

src/ac/ed/lurg/country/CountryAgent.java

src/ac/ed/lurg/country/crafty/CraftyCountryAgent.java

src/ac/ed/lurg/country/gams/GamsCountryInput.java

src/ac/ed/lurg/country/gams/GamsLocationOptimiser.java

src/ac/ed/lurg/demand/CerealFractionsManager.java

src/ac/ed/lurg/types/CommodityType.java