Remove bbtsub.h, duplicate of bbtsubdefs.h. (#294)

`bbtsubdefs.h` and `bbtsub.h` were close to the same. We only
need one.

src/bbtsub.c

@@ -57,6 +57,7 @@
 #include "gcdata.h"
 #include "iopage.h"
 
+#include "bbtsubdefs.h"
 #include "car-cdrdefs.h"
 #include "commondefs.h"
 #include "gcarraydefs.h"
@@ -70,7 +71,6 @@ extern IOPAGE *IOPage68K;
 #include "bb.h"
 #include "bitblt.h"
 #include "pilotbbt.h"
-#include "bbtsub.h"
 #include "dspdata.h"
 #include "display.h"
 #include "dbprint.h"

src/draw.c

@@ -32,10 +32,10 @@
 #include "emlglob.h"
 #include "adr68k.h"
 #include "bitblt.h"
-#include "bbtsub.h"
 #include "display.h"
 
 #include "drawdefs.h"
+#include "bbtsubdefs.h"
 #include "initdspdefs.h"
 
 #ifdef DISPLAYBUFFER

src/rawcolor.c

@@ -32,9 +32,10 @@
 #include "debug.h"
 #include "arith.h"
 #include "bitblt.h"
-#include "bbtsub.h"
 #include "lldsp.h"
 
+#include "bbtsubdefs.h"
+
 #define IMIN(x, y) (((x) > (y)) ? (y) : (x))
 #define IMAX(x, y) (((x) > (y)) ? (x) : (y))
 

src/subr.c

@@ -40,7 +40,6 @@
 #include "arith.h"
 #include "subrs.h"
 #include "dbprint.h"
-#include "bbtsub.h"
 
 #include "subrdefs.h"
 #include "bbtsubdefs.h"