Add MOVELINE command to relocate an existing line

[Lewis Rosenthal]

CUBE lacks the ability to relocate an existing line with all options on it to another place in the same file. This RFE addresses this shortcoming by adding a MOVELINE (ML) command as follows:

MOVELINE        MOVE an existing LINE of Target File from one position to
                another. The d-string identifies the line to be moved. If
                the line is not found within Target File, the new line may
                be added to the Target File.

                ┌───────────────────────────────┐
                │  MOVELINE lineid [( options]  │
                └───────────────────────────────┘

                Command Abbreviation : ML

                lineid      : d-string to identify line

                options     : [ ALL | FIRST | LAST ]
                              [ MOVETOP | MOVEBOTTOM ]
                              [ *ID ]
                              [ RS(x) ]
                              [ IF "x"  ]
                              [ IFNOT "x"  ]

                ALL   : moves ALL occurences of 'lineid' (default)
                FIRST : only moves 1st occurrences of 'lineid'
                LAST  : only moves last occurrence of 'lineid'

                AFTER x  : move after line identified by d-string x.
                           If x is not specified or not present in Target
                           file, line will be added at bottom of Target File.
                BEFORE x : move before line identified by d-string x.
                           If x is not specified or not present in Target
                           File, line will be added at top of Target File.
                ONLY     : with AFTER/BEFORE: move only if x there

                IFNEW x  : add line identified by d-string x if 'lineid' not
                           already there.

                *ID       : target line identification anywhere in the line.

                RS(x)     : replace string(s) within the moved line.
                            x is a single character used as a string delimiter
                            for the duration of this command only; all strings
                            delimited by a pair of x, in the moved line,
                            will be interpreted as environment variable names
                            replaced by their value.

                IF "x"    : Move only if a line identified by "x" exists
                            in the Target File.
                IFNOT "x" : Move only if a line identified by "x"
                            doesn't exist in Target File.

The use case for this type of operation would be to preserve unknown (to CUBE) options on the line while relocating it to another place within the file (typically, CONFIG.SYS).

The RS(x) function allows for the possibility of specifically removing, say, deprecated option parameters from the line being moved while preserving the remainder. New, required, options may be inserted in the moved line in the same way.

IFNEW x allows for ADDLINE processing if no match is found to move.