Vendor raptor source files (was embedded gitlink)

Tree vendored at upstream 0019c5dd; origin + license recorded in
raptor/VENDOR.txt. Windows SDL dev packages excluded via .gitignore.

raptor/src/flame.h

@@ -0,0 +1,6 @@
+#pragma once
+
+void FLAME_Init(void);
+void FLAME_InitShades(void);
+void FLAME_Up(int ix, int iy, int width, int frame);
+void FLAME_Down(int ix, int iy, int width, int frame);