Options for flagging MTOM processing

I took an action item at the F2F to enumerate the options for flagging 
the need to process a message for includes.


* Implicit
Whenever a multipart/related MIME message with an application/soap+xml 
media type is encountered, it should be processed for MTOM-style 
includes.

* In-XML
Need for processing will be flagged by an artifact in the XML payload; 
e.g., a SOAP header block such as "<xbinc:DoIncludes/>".

* New HTTP Header
Need for processing will be flagged by a new HTTP header, e.g., "MTOM: 
process" at the top level of the MIME message.

* New MIME Header
Need for processing will be flagged by a new MIME header, e.g., "MTOM: 
process" associated with the root (SOAP) part of the MIME message.

* HTTP Content-Coding
Need for processing will be flagged by use of a HTTP content-coding, 
e.g., "Content-Encoding: mtom".

* New MIME Content-Type
Need for processing will be flagged by the use of a different 
content-type for the root (SOAP) part; e.g., 
"application/soap-mtom+xml".

* MIME Content-Type Parameters
Need for processing will be flagged by the use of a parameter on the 
"application/soap+xml" media type in the root (SOAP) part; e.g., 
"application/soap+xml; mtom".