request: ^ and constant searching

[Russ Cox]

> I think it would be better to modify the implementation, however.
> For example, if I search for "1,4,9", the squares now appear well down
> the list - because they have an initial 0.  

It's true - I'm not very happy with this and will probably undo this change.

> What I would suggest is that, if the sequence being searched for has a
> value greater than 1, consider it to be an initial match if that matches
> the first value in the sequence that is greater than 1.  So "1,4,9"
> would be an initial match with "0,1,4,9,...", "1,1,4,9,...", but not
> "2,1,4,9,..." or "0,4,9,1,4,9,...".

Well, this wouldn't solve Eric's original problem, which was to find
sequences beginning 2,3,4,5,6,7,8,9,10.  I'm now leaning toward
taking the beginning match part out and just let people who
want to exclude certain results exclude them (e.g., search for
2,3,4,5,6,7 ~1,2,3,4,5,6,7).

I also added wildcards today, so that you can search for 1,2,_,4,5
(match a missing number) or 1,2,__,6,7 (match 1 or more missing
numbers).

Russ