Incorrect handling of continuation lines in fixed-form FORTRAN

[Shimuuar]

It seems that lexer only allows &$+ as continuation chrarcter while FORTRAN 77 standard states that anything but 0 and space could be used.

          3.2.3  Continuation_Line.  A continuation line  is  any
          line   that  contains  any  character  of  the  FORTRAN
          character set other than the  character  blank  or  the
          digit  0 in column 6 and contains only blank characters
          in columns 1 through 5.  A statement must not have more
          than nineteen continuation lines.

For example I have code at hands which uses @ as continuation character

[dorchard]

Thanks for this. We need to add this. Hopefully we can do this soon.