Removed Arduino.h header dependency

src/NeoPixelBus.h

@@ -25,8 +25,6 @@ License along with NeoPixel.  If not, see
 -------------------------------------------------------------------------*/
 #pragma once
 
-#include <Arduino.h>
-
 // some platforms do not come with STL or properly defined one, specifically functional
 // if you see...
 // undefined reference to `std::__throw_bad_function_call()'

src/internal/NeoSettings.h

@@ -25,6 +25,8 @@ License along with NeoPixel.  If not, see
 -------------------------------------------------------------------------*/
 #pragma once
 
+#include <cstdint>
+
 class NeoNoSettings
 {
 };
@@ -59,4 +61,4 @@ public:
     uint16_t GreenTenthMilliAmpere; // in 1/10th ma
     uint16_t BlueTenthMilliAmpere;  // in 1/10th ma
     uint16_t WhiteCurrent; // in 1/10th ma
-};
+};