Double buffer and shader fixes (#273)

* DoubleBufferFixes

* Add NeoBitmapFile Render

src/internal/NeoEspBitBangMethod.h

@@ -113,7 +113,7 @@ public:
         _endTime = micros();
     }
 
-    void Update()
+    void Update(bool)
     {
         // Data latch = 50+ microsecond pause in the output stream.  Rather than
         // put a delay at the end of the function, the ending time is noted and