  \/ Y - Y C H A N G E A L L \/
 Changes all occurrences of one string to another in a range of lines
 Format
 YCHANGEALL <string1>,<string2>,<line #>,<# lines>,<1st pos'n>,<last pos'n>,
<match index>
 Parameters
 <string1>  the string to be searched for and replaced. See L-LOCATE for full
            format details. <string1> must be specified.
 <string2>  the string with which to replace <string1>. Same comments apply
            except <string2> is optional - if omitted it is taken to be null:-
            all occurrences of <string1> in the given range (q.v.) are removed.
 <line #>   First line in which to look for <string1>. Optional - taken as 1
            (i.e. start of file) if not specified.
 <# lines>  # of lines to be searched for <string>. Optional - if ommitted the
            search is done to end of file.
 <1st pos'n> \Much the same as for L-LOCATE. Note however that these params
 <last  "  > /apply to the UNMODIFIED line (before any length change).
 <match index> For regular expressions only (fm +g): specify which match to
               replace. Same as telling L-LOCATE where to leave the cursor:
               H L for more info.
 Notes
 BRIEF or NONE output modes are actioned if in an scmacro without question. If
command came from the keyboard, they are actioned subject to confirmation.
 Specifying neither <line #> or <# lines> scans the whole file.
 The command may be terminated early by a keyboard interrupt (^C usually).
 File position
 Unaltered, except left at a line which won't fit if that happens.
