move utf, fmt to libc

include/libc.h

diff --git a/include/libc.h b/include/libc.h
index 65c23dd..93fa1d0 100644
--- a/include/libc.h
+++ b/include/libc.h
@@ -9,6 +9,9 @@
 extern "C" {
 #endif                                                                
 
+#include <utf.h>
+#include <fmt.h>
+
 /*
  * Begin usual libc.h 
  */

include/u.h

diff --git a/include/u.h b/include/u.h
index ec78ef2..c3f0081 100644
--- a/include/u.h
+++ b/include/u.h
@@ -33,8 +33,6 @@
 #include <assert.h>
 #include <setjmp.h>
 #include <stddef.h>
-#include <utf.h>
-#include <fmt.h>
 #include <math.h>
 #include <ctype.h>	/* for tolower */