Bug fixes. Code cleaned up.

GAMS/IntExtOpt.gms

src/ac/ed/lurg/ModelMain.java

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

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

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

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

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

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

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

src/ac/ed/lurg/utils/DoubleMap.java

src/ac/ed/lurg/utils/NestedMap.java

src/ac/ed/lurg/utils/TripleMap.java