[CM] Snd 12.3

[Bill Schottstaedt]

Snd 12.3

  removed the profiling option in s7.

  all my time in this version went into trying to make s7 faster. 
    I believe it is now 3 times as fast as it was in early May.

  Unless someone objects violently, I'm going to remove the multithreading
    support from s7.  It has turned out to be less useful than I hoped,
    mainly because s7 threads share the heap and therefore have to coordinate
    all cell allocations.  So it's faster, and simpler to use multiple
    pthreads each running a separate s7 interpreter, rather than one s7
    running multiple s7 threads.  In clm, the contention is for access to
    the output stream, so the gain in speed is not always something to
    brag about.  And begin_hook handles GUI-related problems without
    any threads.  Last but not least, the effort to make the non-threaded
    s7 faster has messed up parts of the threaded version.  Rather than
    waste a lot of time fixing this, I'd rather just flush the stuff.

  Due to changes in Gtk, functions like gtk_vbox_new are no longer
    defined in libxm.  This means that several of the gtk-related
    scheme files in the Snd tarball now only work in Gtk 3.0 or later.


checked: gmp 5.0.2, sbcl 1.0.49, gtk 3.1.6|8 (but it looks like crap),
         fftw 3.3beta

Thanks!: Mike Scholz, Fernando Lopez-Lezcano, Rick Taube