FTP Transport

Attached is (literally) a snapshot of what I've written out as a stab 
at getting an FTP transport into ebMS.  This has been an ask that I've 
heard around, and after looking at RFC 949 and reflecting on my 
understanding of FTP, it really is quite trivial.  Maybe not as trivial 
as the specification I've written, but close.

I'd appreciate anyone pointing out anything I've missed, and I'd like 
to have guidance from Dale on how to word the bits that refer to CPA.

Thanks,

Matt