Caching done (a little more closely to) right (I hope).  Reviews, please?
Caching done (a little more closely to) right (I hope).  Reviews, please?

* subversion/libsvn_fs/tree.c
  (SVN_FS_NODE_CACHE_MAX_KEYS): Was SVN_FS_NODE_ID_CACHE_MAX_KEYS.
  (struct dag_node_cache_t): New.
  (struct svn_fs_root_t): Rename 'node_id_cache' to 'node_cache.
    Rename 'node_id_cache_keys' to 'node_cache_keys'.  Add 'node_cache_idx'.
  (make_root): Clear the cache keys array, and init the cache key index.
  (add_to_dag_node_cache): New (cored from get_dag(), with mods).
  (get_dag): Move cache addition stuff into add_to_dag_node_cache().

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion