hotfixes

• fix bg point generation for maxent but needs further monitoring
• new pres/abs plot + associated test
• cc bugfix restore gbm switch which I had accidentally deleted :S
• temporary workaround to try running fine fine scale jobs with categorical input
  • categorical jobs will be cropped on import since unconstrained prediction not generated anyway, saving reprojection/resample of entire layer if not needed
  • just a temp workaround to save on processing time until front end has settings for unconstrained area