#682 Add created() function for sprites

New function added:
  bool created(void);
to check if sprite has been rotated. Example:

if ( !spr.created() ) Serial.println("Sprite has not been created");

Extensions/Sprite.cpp

@@ -112,6 +112,16 @@ void* TFT_eSprite::createSprite(int16_t w, int16_t h, uint8_t frames)
 }
 
 
+/***************************************************************************************
+** Function name:           created
+** Description:             Returns true is sprite has been created
+*************************************************************************************x*/
+bool TFT_eSprite::created(void)
+{
+  return _created;
+}
+
+
 /***************************************************************************************
 ** Function name:           ~TFT_eSprite
 ** Description:             Class destructor