Speedup for pkg_version

[Stephen Montgomery-Smith]

On Sat, 28 Jul 2007, Stephen Montgomery-Smith wrote:

> This is a kludge, but it makes pkg_version 4 times faster on my set up.  The 
> idea is that "make -V PKGNAME" should ordinarily be a very fast operation. 
> So it runs a very cut down version of bsd.port.mk.  If that bombs with an 
> error, then it does the full bsd.port.mk.
>
> Maybe portsmanager and similar tools could use this idea.
>
>

It's not working - it messes up anything where PKGNAMEPREFIX should be set 
to something non-trivial.  E.g. ruby ports.