USER: New class GSort used for handling Sorting preferences. This class sits above analysis classes so that it has full access to possible sorting criteria (inheritance of GoAT was changed for this purpose). A pre-sort is available for sorting on raw tree file variables which is checked before an event is analysed. This is done for speed. A second sort is applied to variables available after analysis (ex. # protons) to determine if the event should be written to file. Also, GoAT init function was changed such that only the config file name is passed to the function and reading of input/output file names is completed within GoAT as opposed to main function.