- move buffer allocation schemes to libbb.h

- include the correct headers: applets need busybox.h while lib* need libbb.h

libbb/get_last_path_component.c

@@ -7,6 +7,8 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
+#include "libbb.h"
+
 char *bb_get_last_path_component(char *path)
 {
 	char *first = path;