On the fsx branch:  Merge the patches pertaining to the new
svn_packed__* private API (r1461865,1462837,1463120,1467362,
1469487,1489817) from /branches/fsfs-format7.

A trivial conflict in svn_error_codes.h had to be resolved
as well as tree conflicts related to fsfs-rework.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx@1507856 13f79535-47bb-0310-9956-ffa450edef68