[CM] Snd 25.8

[bil at ccrma.Stanford.EDU]

Snd 25.8

s7: (*s7* 'scheme-version) which is 's7 by default but can
        be set to 'r5rs or 'r7rs.  The r7rs support is built-in
        if you include the compiler switch -DWITH_R7RS.
        To get a decent repl with both the repl and r7rs built-in,
        use the compiler switches WITH_R7RS and WITH_NOTCURSES.

     added s7_c_object_set_value

     added s7_defun (it handles all the define_*_function and
        make_*_function chores).

checked: sbcl 2.5.9

Thanks!: Jinsar Kafka, Matthew