Cleanup

This is an extract of a commit, minimally edited to ensure it compiles.

Closes #1078.
Related to #197.

src/internal.h

@@ -299,7 +299,6 @@ struct _GLFWwndconfig
     GLFWbool      resizable;
     GLFWbool      visible;
     GLFWbool      decorated;
-    GLFWbool      transparent;
     GLFWbool      focused;
     GLFWbool      autoIconify;
     GLFWbool      floating;
@@ -360,6 +359,7 @@ struct _GLFWfbconfig
     int         samples;
     GLFWbool    sRGB;
     GLFWbool    doublebuffer;
+    GLFWbool    transparent;
     uintptr_t   handle;
 };
 
@@ -403,7 +403,6 @@ struct _GLFWwindow
     // Window settings and state
     GLFWbool            resizable;
     GLFWbool            decorated;
-    GLFWbool            transparent;
     GLFWbool            autoIconify;
     GLFWbool            floating;
     GLFWbool            shouldClose;