[CM] Snd 11.10

[Bill Schottstaedt]

Mike made innumerable improvements in the scripts.

snd7.scm and snd8.scm removed.

defgenerator replaces def-clm-struct.

deprecated verbose-cursor (use with-verbose-cursor).

added 'gtk3 or 'gtk2 to *features*.  (The gtk3 version has many
    problems).

s7: added setters for current-input-port, current-output-port, 
       and current-error-port.

    *stdin*, *stdout*, *stderr* as the default IO ports 
       (rather than nil which is ambiguous).

    removed special variable (dynamic binding) support (it gets
       in the way of tail recursion).

    s7_call_with_location to improve error handling.

    s7 is about 10% faster in this version -- there are timings
       at the end of s7.c and snd-test.scm.

checked: autoconf 2.68, sbcl 1.0.43, gtk 2.91.0|1, gmp 5.0.1

Thanks!: Mike Scholz