Problem: When 'wrapscan' is off "gn" does not select the whole pattern when
it's the last one in the text. (KeyboardFire)
Solution: Check if the search fails. (Christian Brabandt, closes#1683)
Problem: "cgn" and "dgn" do not work correctly with a single character
match and the replacement includes the searched pattern. (John
Beckett)
Solution: If the match is found in the wrong column try in the next column.
Turn the test into new style. (Christian Brabandt)
