= Join lines

        JOIn  { X | NX | [n[-b-s]] } [ all ]  [ .lab1 .lab2 ]

            Concatenate to lines.

            X    :conactination of excluded part.
            NX   :conactination of not-excluded part.
            n    :lines to be concatenate to a line.
            b    :repeat n lines concatenation.
            s    :skip s lines after n times repeat.
            all  :in the whole of file.
                  When X or NX,
                  without all,part is searched from the current cursor
                  position.RepeatCmd(Ctl+F12) support to repeat JOI cmd
                  without changing cursor position.
            .lab :join in the range of .lab1 and .lab2.