"Virtual" connection identifier should be a UUID4, not an integer counter

[glyph]

glyph did not know things about cryptographic security when he wrote this

[glyph]

The relevant AMP command is in vertex.command.Virtual

[glyph]

Choke and Unchoke both refer to the same kind of connection ID

[glyph]

There's also a couple of callRemoteString invocations which imply AMP commands on vertex.q2q.VirtualTransport and the amp_WRITE and amp_CLOSE methods on Q2Q.

[glyph]

This might not actually be necessary. The comment about cryptographic security above was somewhat misguided, since the identifiers are scoped to the (authenticated) connection.