On the fsfs-format7 branch: minor refactoring.

* subversion/libsvn_fs_fs/index.h
  (svn_fs_fs__p2l_entry_dup): declare here; renamed from copy_p2l_entry
* subversion/libsvn_fs_fs/index.c
  (svn_fs_fs__p2l_entry_dup): move implementation from pack.c to here

* subversion/libsvn_fs_fs/pack.c
  (copy_p2l_entry): remove here
  (copy_item_to_temp,
   copy_rep_to_temp, 
   copy_node_to_temp,
   write_changes_container): update callers


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1476632 13f79535-47bb-0310-9956-ffa450edef68