avoid the need for additional includes for task interfaces

lib/buttontask/GwButtonTask.h

@@ -4,4 +4,19 @@
 //task function
 void initButtons(GwApi *param);
 DECLARE_INITFUNCTION(initButtons);
+
+class IButtonTask : public GwApi::TaskInterfaces::Base
+{
+public:
+    typedef enum
+    {
+        OFF,
+        PRESSED,
+        PRESSED_5, // 5...10s
+        PRESSED_10 //>10s
+    } ButtonState;
+    ButtonState state=OFF;
+    long pressCount=0;
+};
+DECLARE_TASKIF(IButtonTask);
 #endif