get rid of XFree86LOADER, XFree86Server, XFree86Module, and IN_MODULE

Get rid of almost all uses of these definitions.  They're still defined for
delinquent out-of-tree drivers, and also for the Mesa build.  As well as
for miinitext.c.  But largely gone.

fb/fb24_32.c

@@ -28,9 +28,6 @@
 #endif
 
 #include <string.h>
-#ifdef XFree86LOADER
-#include "xf86.h"
-#endif
 
 #include "fb.h"