Fix a noderev caching inefficiency on 32 bit machines.

* subversion/libsvn_fs_fs/cached_data.c
  (get_node_revision_body): fully initialize the cache key

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1519281 13f79535-47bb-0310-9956-ffa450edef68
Since FSFS format 7 is going to add even more small, frequently accessed
objects that need caching, double the releative size of the cache index
table to 20% of the total cache size.

* subversion/libsvn_subr/cache_config.c
  (svn_cache__get_global_membuffer_cache): bump index table size

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1519282 13f79535-47bb-0310-9956-ffa450edef68