#1: You cannot change Diff options while the side-by-side diff window is open.
#2: Once #1 is fixed: During a side-by-side right click on a line with differences and in the context menu there should be an "Add difference to Token Mapping"
Selecting that would open the TokenMapping "Add Item" with left and right prepopulated with the left and right lines of the files.
Exactly what text to add? Several possibilities:
1 The entire lines.
2 Just the range of text from the left and right from the left most diff to the right most diff.
3 Same as 2, plus a few extra characters fudge factor.
