Create 1.8 backport branch for r1578853.

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x-r1578853@1578879 13f79535-47bb-0310-9956-ffa450edef68
On 1.8.x-r1578853 branch, merge r1578853 and r1578875 and resolve text conflict.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x-r1578853@1578885 13f79535-47bb-0310-9956-ffa450edef68
Merge the 1.8.x-r1578853 branch:

 * r1578853, r1578875
   Fix svnserve to only send inherited properties when necessary.
   Justification:
     Performance regression from 1.7, reported by a user.
   Branch:
     ^/subversion/branches/1.8.x-r1578853
   Votes:
     +1: philip, rhuijben, ivan


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1581683 13f79535-47bb-0310-9956-ffa450edef68