initial commit

took me a day to make the base...
...and ~12 hours to write a reader that reads 100% of all demo songs in
1.0

src/engine/platform/dummy.h

@@ -0,0 +1,10 @@
+#include "../dispatch.h"
+
+// the dummy platform outputs square waves, interprets STD instruments and plays samples.
+// used when a DivDispatch for a system is not found.
+class DivPlatformDummy: public DivDispatch {
+  public:
+    void acquire(float& l, float& r);
+    int dispatch(DivCommand c);
+    int init(int channels);
+};