Cleanup of includes and related changes based on include-what-you-use diagnostics (#436)

Remove unused #define PERCENT_OF_SCREEN in MyWindow.h
Move structures for dir.c to dirdefs.h where they are used
Resolve S_CHAR vs S_CHARACTER in favor of S_CHARACTER and cleanup #defines
Fix  = vs == bug in FSDEBUG code in dir.c
Eliminate duplicate/unused constant definitions in gcr.c
Declare static internal function bytecmp in mkatom.c
Update many source and include files to include headers for what they use

src/kprint.c

@@ -10,21 +10,18 @@
 
 #include "version.h"
 
-#include <stdio.h>
-#include "print.h"
-#include "address.h"
-#include "lispemul.h"
-#include "lsptypes.h"
-#include "lspglob.h"
-#include "initatms.h"
-#include "cell.h"
+#include <stdio.h>         // for printf
+#include "address.h"       // for LOLOC
+#include "adr68k.h"        // for Addr68k_from_LADDR
+#include "car-cdrdefs.h"   // for cdr, car
 #include "emlglob.h"
-#include "lispmap.h"
-#include "adr68k.h"
-
-#include "kprintdefs.h"
-#include "car-cdrdefs.h"
-#include "testtooldefs.h"
+#include "kprintdefs.h"    // for prindatum, print, print_NEWstring, print_fixp
+#include "lispemul.h"      // for LispPTR, DLbyte, DLword, POINTERMASK, NIL
+#include "lispmap.h"       // for S_POSITIVE
+#include "lspglob.h"
+#include "lsptypes.h"      // for NEWSTRINGP, GETBYTE, GetTypeNumber, TYPE_L...
+#include "print.h"         // for DOUBLEQUOTE, RIGHT_PAREN, LEFT_PAREN, SPACE
+#include "testtooldefs.h"  // for print_atomname
 
 int PrintMaxLevel = 3;
 int Printdepth = 0;