3 - Implement & test read-sequence, write-sequence for (un)signed-8 vectors
5 - Make reader work with simple-streams
7 - external format handling: load aliases, load formats, etc.
9 - Handle writing beyond the end of a mapped-simple-stream properly
11 - handle device-file-position for mapped streams
13 - Test write-octets / read-octets handling of encapsulated streams
15 - handle ansi-streams in write-octets / read-octets?
17 - Implement socket-base-simple-stream and chunked transfer encoding.
19 - Test string streams.
21 - Make sure the code examples for stream encapsulation from Franz work
23 - Test every single output function
25 - Test character position (slot charpos)
27 - make pathname work for simple-streams
29 - test :abort argument to close (should revert to original file)