implemented test input syntax for testing program operations

encoder test input syntax consists of +/- for insert/delete followed by
the line index number and optional spaces, + with no number is insert at
end of program (append), line index number with no +/- is replace line,
and no syntax is still append to end of program; when using syntax, the
Input: and Output: lines are suppressed from the output

added encoder test #2, which is a clone of test #1 with + on all lines
followed by several different program operation lines (various replace,
insert and delete operations)