On the log-addressing branch:
Make LINE_CHUNK_SIZE part of our private I/O API.  Other parts such as
the FSFS f7 code may use this information to e.g. optimize data layout.

* subversion/include/private/svn_io_private.h
  (SVN__LINE_CHUNK_SIZE): move, rename & document constant taken from ...

* subversion/libsvn_subr/stream.c
  (LINE_CHUNK_SIZE): ... here
  (stream_readline_bytewise,
   stream_readline_chunky): update users

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/log-addressing@1533539 13f79535-47bb-0310-9956-ffa450edef68