GUI: try using FFTW for per-chan osc wave center

not reliable yet

extern/fftw/kernel/alloc.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2003, 2007-14 Matteo Frigo
+ * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "kernel/ifftw.h"
+
+void *X(malloc_plain)(size_t n)
+{
+     void *p;
+     if (n == 0)
+          n = 1;
+     p = X(kernel_malloc)(n);
+     CK(p);
+
+#ifdef MIN_ALIGNMENT
+     A((((uintptr_t)p) % MIN_ALIGNMENT) == 0);
+#endif
+
+     return p;
+}
+
+void X(ifree)(void *p)
+{
+     X(kernel_free)(p);
+}
+
+void X(ifree0)(void *p)
+{
+     /* common pattern */
+     if (p) X(ifree)(p);
+}