parse syntax error caret indicator missing in 6

[Colin Macdonald]

The caret syntax error indicator seems to missing in 6.0.  Is this a 
regression?  Its still mentioned in doc/interpreter/basics.txi

In 5.2:

```
octave:1> 1 + (2 + !)
parse error:

  syntax error

>>> 1 + (2 + !)
              ^

```

In 6.0 and 7.0 from git/hg:

```
1 + (2 + !))
error: parse error:

  syntax error

```
(tested with today's tip and much older 6.0 stable)

I have a vague sense this was discussed, so apologies if this is a dupe.

thanks,
Colin

--
Colin Macdonald
Associate Professor
Dept of Math, UBC