Change to Lock-Token

As I was working through versioning I realized I had made a mistake in
specifying the Lock-Token header. I want lock-tokens to be
quoted-strings, instead of tokens, so they can be used anywhere an e-tag
may be used.
		Yaron

Lock-Token Header

LockToken = "Lock-Token" ":" quoted-string CRLF

The Lock-Token may be used anywhere that an e-tag may be used. So
Lock-Tokens may be used in if-match calls to indicate that the request
may only proceed if the lock is still in force.
The LockToken header may never appear in the same request as a Lock-Info
header.