Add print tree support (horizontal)

Horizontal tree print fills all my needs

print_helper.c

@@ -44,3 +44,32 @@ void print_char(char c)
 		break;
 	}
 }
+
+void print_tree(struct tree *parent)
+{
+	int level = 1;
+	while (parent->left != NULL ) {
+		for (int i = 0; i < level; i++) {
+			printf(" ");
+		}
+		if (parent->right)
+			print_char(parent->right->ch);
+
+		for (int i = 0; i < level-1; i++) {
+			printf(" ");
+		}
+		printf("o\n");
+
+		for (int i = 0; i < level; i++) {
+			printf(" ");
+		}
+
+		if (parent->left && parent->left->ch != 0)
+			print_char(parent->left->ch);
+		else
+			printf("o\n");
+
+		level += 2;
+		parent = parent->left;
+	}
+}

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 */
 
+#include "tree.h"
+
 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #define for_endian(size) for (int i = 0; i < size; ++i)
 #elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
@@ -18,3 +20,4 @@ void __printb(void *value, size_t size);
 })
 
 void print_char(char c);
+void print_tree(struct tree *parent);