Selection.m width: a fix for rotated pages

[ldenoue]

Sometimes on rotated pdf files the textMatrix.a is 0.
An example is here: http://94.23.146.173/ficheros/d412df0c4d6c05406e5dd5757ea63ae1.pdf

In these cases, we need to return the vertical.

CGFloat vertical(CGAffineTransform transform) {
return transform.ty / transform.b;
}

• (CGFloat)width {
  CGFloat a = self.finalState.textMatrix.a;
  CGFloat a2 = self.initialState.textMatrix.a;
  if (a == 0 || a2 == 0)
  return vertical(self.finalState.textMatrix) - vertical(self.initialState.textMatrix);
  else
  return horizontal(self.finalState.textMatrix) - horizontal(self.initialState.textMatrix);
  }