fix up jumps when we add/remove rows

def fix_jumps(self, row_selected, delta):
        '''fix up jumps when we add/remove rows'''
        numrows = self.grid_mission.GetNumberRows()
        for row in range(numrows):
            command = self.grid_mission.GetCellValue(row, ME_COMMAND_COL)
            if command in ["DO_JUMP", "DO_CONDITION_JUMP"]:
                p1 = int(float(self.grid_mission.GetCellValue(row, ME_P1_COL)))
                if p1 > row_selected and p1+delta>0:
                    self.grid_mission.SetCellValue(row, ME_P1_COL, str(float(p1+delta)))