Merge branch 'master' of https://github.com/tildearrow/furnace into x1_010

# Conflicts:
#	CMakeLists.txt
#	papers/doc/7-systems/README.md
#	src/engine/dispatch.h
#	src/engine/dispatchContainer.cpp
#	src/engine/playback.cpp
#	src/engine/sysDef.cpp
#	src/gui/gui.cpp

src/engine/dispatch.h

@@ -116,6 +116,9 @@ enum DivDispatchCmds {
   DIV_CMD_X1_010_ENVELOPE_SLIDE,
   DIV_CMD_X1_010_AUTO_ENVELOPE,
 
+  DIV_CMD_WS_SWEEP_TIME,
+  DIV_CMD_WS_SWEEP_AMOUNT,
+
   DIV_ALWAYS_SET_VOLUME,
 
   DIV_CMD_MAX
@@ -323,6 +326,11 @@ class DivDispatch {
      */
     virtual void notifyInsDeletion(void* ins);
 
+    /**
+     * notify that playback stopped.
+     */
+    virtual void notifyPlaybackStop();
+
     /**
      * force-retrigger instruments.
      */