On the fsfs-format7 branch:  Increase the cache retention rate of key data
structures by raising their priority.  These are noderevs and manifests
(used by pre-format7 only).  Because packed revprops are relatively expensive
to read, try to keep them in cache as well.

* subversion/libsvn_fs_fs/caching.c
  (svn_fs_fs__initialize_caches): bump prio for manifests, noderevs, revprops

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsfs-format7@1446105 13f79535-47bb-0310-9956-ffa450edef68