Update tuklib base headers to include stdbool.h.

src/common/tuklib_common.h

@@ -14,7 +14,7 @@
 #define TUKLIB_COMMON_H
 
 // The config file may be replaced by a package-specific file.
-// It should include at least stddef.h, inttypes.h, and limits.h.
+// It should include at least stddef.h, stdbool.h, inttypes.h, and limits.h.
 #include "tuklib_config.h"
 
 // TUKLIB_SYMBOL_PREFIX is prefixed to all symbols exported by

src/common/tuklib_config.h

@@ -2,6 +2,7 @@
 #	include "sysdefs.h"
 #else
 #	include <stddef.h>
+#	include <stdbool.h>
 #	include <inttypes.h>
 #	include <limits.h>
 #endif