unprotectedAreas, minimumLandCover and GAMS calc. changes/fixes.

GAMS/IntExtOpt.gms

src/ac/ed/lurg/ModelConfig.java

src/ac/ed/lurg/Timestep.java

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

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

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

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

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

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

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

src/ac/ed/lurg/landuse/LandUseItem.java