On the fsfs-format7 branch: fix a few bugs in the change list container.
Also, remove unused functions from the API.

* subversion/libsvn_fs_fs/changes.h
  (svn_fs_fs__changes_start_list,
   svn_fs_fs__changes_append_change): drop unused API

* subversion/libsvn_fs_fs/changes.c
  (svn_fs_fs__changes_start_list,
   svn_fs_fs__changes_append_change): remove implemenation
  (append_change_body): rename to ...
  (append_change): ... this; fix construction of FLAGS
  (svn_fs_fs__changes_append_list): terminate list *after* adding changes
  (svn_fs_fs__changes_get_list): fix copy-n-pasto


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1469507 13f79535-47bb-0310-9956-ffa450edef68