Rewrote mkdir (and touched lots of things in the process).
diff --git a/libbb/libbb.h b/libbb/libbb.h
index e42ca9f..c83cb7e 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -243,6 +243,10 @@
 
 extern struct hostent *xgethostbyname(const char *name);
 
+char *dirname (const char *path);
+char *strdup_substr (const char *s, int start, int end);
+int make_directory (char *path, mode_t mode, int flags);
+
 #define CT_AUTO	0
 #define CT_UNIX2DOS	1
 #define CT_DOS2UNIX	2