VCL syntax change

[Poul-Henning Kamp]

I have changned the VCL syntax for strings so that regexps on
URLs do not become a nightmarish maze of back-slashes.

We recognize %xx escapes now, but until we know a use for them,
it will balk at any that turns into a control character.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.