Bug #26461: Intrinsic data type bool (1 byte) redefined to BOOL (4 bytes)

The bool data type was redefined to BOOL (4 bytes on windows).
Removed the #define and fixed some of the warnings that were uncovered
by this.
Note that the fix also disables 2 warnings :
4800 : 'type' : forcing value to bool 'true' or 'false' (performance warning)
4805: 'operation' : unsafe mix of type 'type' and type 'type' in operation

These warnings will be handled in a separate bug, as they are performance related or bogus.

Fixed to int the return type of functions that return more than 
2 distinct values.

include/config-win.h

@@ -157,14 +157,12 @@ typedef uint rf_SetTimer;
 
 #define Socket_defined
 #define my_socket SOCKET
-#define bool BOOL
 #define SIGPIPE SIGINT
 #define RETQSORTTYPE void
 #define QSORT_TYPE_IS_VOID
 #define RETSIGTYPE void
 #define SOCKET_SIZE_TYPE int
 #define my_socket_defined
-#define bool_defined
 #define byte_defined
 #define HUGE_PTR
 #define STDCALL __stdcall	    /* Used by libmysql.dll */
@@ -457,4 +455,4 @@ inline double ulonglong2double(ulonglong value)
 #define HAVE_CHARSET_ujis 1
 #define HAVE_CHARSET_utf8 1
 #define HAVE_UCA_COLLATIONS 1
-
+#define HAVE_BOOL 1

include/my_global.h

@@ -980,7 +980,7 @@ typedef int		myf;	/* Type of MyFlags in my_funcs */
 typedef char		byte;	/* Smallest addressable unit */
 #endif
 typedef char		my_bool; /* Small bool */
-#if !defined(bool) && !defined(bool_defined) && (!defined(HAVE_BOOL) || !defined(__cplusplus))
+#if !defined(bool) && (!defined(HAVE_BOOL) || !defined(__cplusplus))
 typedef char		bool;	/* Ordinary boolean values 0 1 */
 #endif
 	/* Macros for converting *constants* to the right type */