Fix more imports.

dulwich/object_store.py

@@ -18,11 +18,13 @@
 
 from dulwich.objects import (
         hex_to_sha,
+        sha_to_hex,
         ShaFile,
         )
 from dulwich.pack import (
         iter_sha1, 
         load_packs, 
+        write_pack,
         write_pack_data,
         write_pack_index_v2,
         PackData, 

dulwich/pack.py

@@ -577,7 +577,7 @@ def write_pack_data(f, objects, num_objects, window=10):
     """Write a new pack file.
 
     :param filename: The filename of the new pack file.
-    :param objects: List of objects to write.
+    :param objects: List of objects to write (tuples with object and path)
     :return: List with (name, offset, crc32 checksum) entries, pack checksum
     """
     recency = list(objects)