Minor issue: Do we want to support only output recording streams, or do we want to support
output recording sheets as well? If the latter, we need to split apart graphics output recording
and textual output recording, and rename lots of things. | SWM

=> output-recording-stream [Protocol Class]
The protocol class that indicates that a stream is an output recording stream. If you want
to create a new class that behaves like an output recording stream, it should be a subclass of
output-recording-stream. Subclasses of output-recording-stream must obey the output
recording stream protocol.

=> output-recording-stream-p object [Function]
Returns true if object is an output recording stream, otherwise returns false.

=> standard-output-recording-stream [Class]
The class used by CLIM to implement output record streams. This is a subclass of output-
recording-stream. Members of this class are mutable.

16.4.1 The Output Recording Stream Protocol

The following generic functions comprise the output recording stream protocol. All subclasses
of output-recording-stream must implement methods for these generic functions.

=> stream-recording-p stream [Generic Function]
Returns true when the output recording stream stream is recording all output performed to it,
otherwise returns false.

=> (setf stream-recording-p) recording-p stream [Generic Function]
Changes the state of stream-recording-p to be recording-p, which must be either t or nil.

=> stream-drawing-p stream [Generic Function]
Returns true when the output recording stream stream will actually draw on the viewport when
output is being performed to it, otherwise returns false.

=> (setf stream-drawing-p) drawing-p stream [Generic Function]
Changes the state of stream-recording-p to be drawing-p, which must be either t or nil.