Add several additional test cases to FishersExact unit test.   Passes all reference tables from Mehta and Patel and Clarkson, Fan, and Joe.
Add several additional test cases to FishersExact unit test.   Passes all reference tables from Mehta and Patel and Clarkson, Fan, and Joe.

brysonda/apto,brysonda/apto,devosoft/apto,devosoft/apto