[CFT] patch to replace the regex code

[Gabor Kovesdan]

> Forgive me if I'm patronizing, but is there any surprise that a POSIX 
> NFA implementation is slower than grep's DFA?
>
Oh, of course an NFA implementation will always be slightly slower but 
the memory footprint will also be smaller, which is a big advantage for 
embedded systems. But in this case, the basis of the comparison was not 
the GNU DFA implementation but the old libc-regex. At the moment, BSD 
grep in the base system uses the GNU regex engine but I built a local 
version for testing purposes that used libc-regex.

Gabor