Increased speed for high res video 4K (3840 x 2026) 30-40 FPS.

AlexeyAB

2017-06-30 42d06a74855c7fae94a86d2da989239d1e1c17ee

 src/stb_image_write.h

@@ -279,7 +279,7 @@
{
   unsigned char scanlineheader[4] = { 2, 2, 0, 0 };
   unsigned char rgbe[4];
   float linear[3];
   float linear[3] = {0};
   int x;

   scanlineheader[2] = (width&0xff00)>>8;