added rudimentary shake effect

io/config.cpp

@@ -14,6 +14,7 @@ bool custom_scale = false;
 bool saved_layout = false;
 bool left_mouse_dominant = true;
 bool show_track_lines = false;
+bool scroll_zooms = false;
 
 void load_config() {
 	/*if (!custom_scale) {

io/config.h

@@ -10,6 +10,8 @@ extern bool custom_scale;
 extern bool saved_layout;
 extern bool show_track_lines;
 
+extern bool scroll_zooms;
+
 void load_config();
 void save_config();