[WFCORE-148] Input stream response attachments

Support for attachment of input streams to management responses with:

1) Propagation to a remote ModelControllerClient over the management protocol
2) Propagation throughout the domain (e.g. server to HC to DC)
3) Ability of HTTP clients to use a query parameter (?useStreamAsResponse=0) or HTTP header ("org.wildfly.useStreamAsResponse : 0") to request the stream as the response instead of the normal JSON. In the examples above the '0' is not necessary, as it is the default.

See http://lists.jboss.org/pipermail/wildfly-dev/2014-October/003070.html

The first commit here is basically what's described above.

The second commit is concerned with cleaning up streams that the client never reads. A background task executes every 10 seconds and closes any streams associated with a particular operation if no such stream has been accessed in the past 30 seconds. This is relevant to native API requests; the HTTP handler will close all streams after responding to the client. But a native client needs to read or close the streams themselves, so a cleanup method is needed in case they fail to do so.

If a stream is read by a native client, the server-side stream is automatically closed once all bytes are sent to the client. The client does not need to close it.
The context will be eligible for gc once that statement executes so the only live ref to the map will be this one.