update FlipDotDrv and add scrolling text feature

include/FlipDotDrv.h

@@ -21,15 +21,13 @@ private:
     uint16_t FrameDataLength;
     uint16_t bufferLength;
 
-    GFXcanvas1 myCanvas;
-
 public:
     FlipDotDrv(uint8_t width, uint8_t height, uint8_t address);
     ~FlipDotDrv();
 
     void sendRaw(const uint8_t* bmp, uint16_t length);
 
-    void printText(const char* txt, uint8_t multiplier = 1);
-    void printText(const char* txt, uint8_t x, uint8_t y, uint8_t multiplier = 1);
+    void sendCanvas(const GFXcanvas1 * canv);
+
 };