Merge r1581296 from trunk:

 * r1581296
   Reduce buffer size used for parsing config files. There no reason to waste 
   100kb of memory -- 16kb is enough to avoid I/O overhead.
   Justification:
     Significantly reduce server memory footprint on high load.
   Votes:
     +1: ivan, rhuijben, kotkov


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1585643 13f79535-47bb-0310-9956-ffa450edef68
Merge r1583977 from trunk:

 * r1583977
   Do not leave dead transaction if commit was blocked by start-commit hook.
   Justification:
     Leaving dead transaction is not good thing. Regression from 1.7.
   Votes:
     +1: ivan, rhuijben, kotkov


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1585644 13f79535-47bb-0310-9956-ffa450edef68