Fix for land allocation error in allocAreas method. Unprotected natural area was being calculated on more that one occasion within a timestep resulting in changing proportions of 'other natural' and 'forest' that should be protected. Area(s) of natural land that should be protected now updated at the start of each timestep and remain constant throughout the timestep.

Changes to fix suitable area aggregation difference, honour protected areas and remove double clustering.

Changes to set in GAMS intensities from previous run, as starting point.  Also changes for dry matter, and some tidy-up.

incorporating trade barriers. trade barriers only affect exports. rather than calculate global export calculate country export (global export * scaler for country). Parameter in GAMS still called worldExportPrice. Perhaps needs to be changed to country.