Gray streams
"Gray Streams" are a generic function wrapping of the COMMON-LISP streams in the standard library, allowing for further specialization by end users.

This interface was proposed for inclusion with ANSI CL by David N. Gray in Issue STREAM-DEFINITION-BY-USER. The proposal did not make it into ANSI CL, but most popular CL implementations implement this facility anyway.

NEED: status of working implementation xrefd. with trivial-gray-streams

proposed extensions to ANSI