Support tunneling of bumped non-HTTP traffic. Other SslBump fixes.

Support tunneling of bumped non-HTTP traffic. Other SslBump fixes.

Use case: Skype groups appear to use TLS-encrypted MSNP protocol instead
of HTTPS. This change allows Squid admins using SslBump to tunnel Skype
groups and similar non-HTTP traffic bytes via "on_unsupported_protocol
tunnel all". Previously, the combination resulted in encrypted HTTP 400
(Bad Request) messages sent to the client (that does not speak HTTP).

Also this patch:
 * fixes bug 4529: !EBIT_TEST(entry->flags, ENTRY_FWD_HDR_WAIT)
   assertion in FwdState.cc.

 * when splicing transparent connections during SslBump step1, avoid
   access-logging an extra record and log %ssl::bump_mode as the expected
   "splice" not "none".

 * handles an XXX comment inside clientTunnelOnError for possible memory
   leak of client streams related objects

 * fixes TunnelStateData logging in the case of splicing after peek.

This is a Measurement Factory project.