Refactor the test code
Refactor the input test
Cleanup
Refactor R script logregr_group_test.R
Fixed a bug in global_init_file
logregr with nulls

fixed input tests and unfinished changes for output tests
Added new data for null handling
Minor changes
Update group output answers
Grouping test passed
Finished all input output tests for NULL handling
Corrected some bugs in null handling test
Corrected a dataset, allow to use boolean values
Adjusted the R script locations
Update tests