The server SHOULD offer compact direct-connect and Push Alt Locs in 
the new header "X-ALT:"

        X-ALT:  ( <DALT> | <PALT> )

        DALT:   ( <IP>[:<PORT>] )

        PALT:   ( <GUID>(;<DALT>)+ )

        IP:     ( standard string representation of an IP Address.
                  i.e. Typical dotted IP Address a.b.c.d )

        PORT:   ( text number representing the port.
                  If 6346, you MAY omit it )

        GUID:   ( Base32 encoded version of the proxied hosts'
                  16-byte Gnutella GUID )

        Example:

                X-ALT: a.b.c.d:e
                X-ALT: f.g.h.i:j
                X-ALT: <GUID>;k.l.m.n:o;p.q.r.s:t

                =

                X-ALT: a.b.c.d:e,f.g.h.i:j,<GUID>;k.l.m.n:o;p.q.r.s:t

[Update of 2010-03-01]

Actually, firewalled alt-locs are not sent in X-Alt but in X-Falt, and then
only if the remote party advertised the "fwalt" (for firewalled altloc)
feature in his X-Feature header.

The format of X-Falt is the following at least:

	X-Falt: <GUID>;a.b.c.d:e;p.q.r.s:t

i.e. it lists the GUID of the host and a list of push-proxies as IP:port,
corresponding to the known proxies of that GUID.

LimeWire prefixes the push-proxy list with "pptls=<hex>" to signal which
of the push-proxies support TLS, but the format of the bitfield represented
in "<hex>" is unknown.
