In FSX, remove all code that reads and writes noderev IDs in changed path lists.
* subversion/libsvn_fs_x/changes.c (CHANGE_TXN_NODE): No longer needed. (binary_change_t): Remove noderev ID element. (append_change, svn_fs_x__changes_get_list, svn_fs_x__write_changes_container, svn_fs_x__read_changes_container, svn_fs_x__changes_get_list_func): Remove all noderev ID access for containered changed paths lists.
* subversion/libsvn_fs_x/low_level.c (read_change, write_change_entry): No longer read and write noderev IDs when reading / writing non-packed changes lists.
* subversion/libsvn_fs_x/transaction.c (fold_change): The noderev ID is now meaningless here. (svn_fs_x__add_change): Don't store the noderev ID anymore. (write_final_rev): No longer update the noderev in changed paths lists. (sanitize_changed_path_info): No longer neccessary. (commit_body): Update caller.