Sunny-shine's new techniques

[SudokuMonster]

I added the WXYZ wing … Sunny-Shine's repository forked into our repository for reference New additions are in Branch "Sunny-shine"

The changes which were made to Grid, Cell made the adding this time consuming. I suspect the same has to be done to the rest (VWXYZ wing, W-Wing and Turbot Fish). There are techniques under construction which would be appearing when Sunny-shine's updated their repository