optimised successors function for sudoku to use the most complete row, column or sub-square
Added helper functions for selecting next position to solve for sudoku
Heuristics for Sudoku updated and tested for A*, works but slow, 30 seconds

refactored

Queens problem, solved. Does not look pretty. Successor, is allowed and is goal completed. Breadth first function still not touched

touch up

breadth first algorithm untouched. Sudoku Successors and allowed moves completed. Tested with solution testing.py. Sudoku is_goal also completed

first commit breadth first search, algorithm done. Is_goal and Successors is jst skeleton code