Fix header file usage -- there were many unnecessary header files included in
busybox.h which slowed compiles.  I left only what was needed and then fixed up
all the apps to include their own header files.  I also fixed naming for pwd.h
and grp.h functions.  Tested to compile and run with libc5, glibc, and uClibc.
 -Erik
diff --git a/coreutils/dirname.c b/coreutils/dirname.c
index 63c557a..333f08d 100644
--- a/coreutils/dirname.c
+++ b/coreutils/dirname.c
@@ -22,6 +22,8 @@
  */
 #include "busybox.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 extern int dirname_main(int argc, char **argv)
 {