Remove unneeded headers, bring consistency.

Use same style on all files and add guards to headers, where missing.

bit-buffer.c

@@ -16,7 +16,6 @@
 */
 
 #include <stdlib.h>
-#include <stdio.h>
 
 #include "bit-buffer.h"
 

bit-buffer.h

+
 #ifndef _BIT_BUFFER_H_
 #define _BIT_BUFFER_H_
 

header.c

-#include <stdio.h>
+
 #include <stdlib.h>
 
-#include "tree.h"
-#include "bit-buffer.h"
 #include "print_helper.h"
 
 static int write_entries(struct BIT_BUFFER *bitbuf, struct tree *parent)

header.h

 
+#ifndef _HEADER_H_
+#define _HEADER_H_
+
 #include "bit-buffer.h"
 #include "tree.h"
 
 int encode_header(struct BIT_BUFFER *bitbuf, struct tree *parent);
 int decode_header(struct BIT_BUFFER *bitbuf, struct tree *parent);
+
+#endif /* _HEADER_H_ */

huffman.c

+
 #include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 
-#include "print_helper.h"
-
 #include "header.h"
-#include "tree.h"
+#include "print_helper.h"
 
 void free_tree(struct tree *parent)
 {

print_helper.c

-/* I DO NOT OWN THIS CODE. */
-/* From http://stackoverflow.com/questions/111928/is-there-a-printf-converter-to-print-in-binary-format?page=2&tab=votes#tab-top */
 
-#include <stdio.h>
 #include <stdint.h>
 #include <string.h>
 
 #include "print_helper.h"
 
+/* From http://stackoverflow.com/questions/111928/is-there-a-printf-converter-to-print-in-binary-format?page=2&tab=votes#tab-top */
 void __printb(void *value, size_t size)
 {
 	uint8_t byte;

print_helper.h

-/* I DO NOT OWN THIS CODE. */
-/* From http://stackoverflow.com/questions/111928/is-there-a-printf-converter-to-print-in-binary-format?page=2&tab=votes#tab-top */
+
+#ifndef _PRINT_HELPER_H_
+#define _PRINT_HELPER_H_
 
 #include "tree.h"
 
@@ -21,3 +22,5 @@ void __printb(void *value, size_t size);
 
 void print_char(unsigned char c);
 void print_tree(struct tree *parent);
+
+#endif /* _PRINT_HELPER_H_ */

tree.c

-#include <stdio.h>
+
 #include <stdlib.h>
-#include <string.h>
 
 #include "tree.h"
-#include "bit-buffer.h"
 
 /* The character set we support */
 #define MY_BUF 256

tree.h

+
 #ifndef _TREE_H_
 #define _TREE_H_