BATCH_CONFIG and CONTEXT_CONFIG should only be class definitions at the time of using PropertyGrid

Both BATCH_CONFIG and CONTEXT_CONFIG are class definition objects but are used as simple structures except at the time of displaying the PropertyGrid GUI. The class definition and PopertyGrid GUI make this incompatible with Octave at this time but are otherwise unnecessary for the functioning of the extension. These variables should be treated entirely as structures except at the time of displaying the PropertyGrid GUI.