Merge branch 'lt/config-fsync' into maint

* lt/config-fsync:
  Add config option to enable 'fsync()' of object files
  Split up default "i18n" and "branch" config parsing into helper routines
  Split up default "user" config parsing into helper routine
  Split up default "core" config parsing into helper routine

diff --cc Documentation/config.txt
Simple merge

diff --cc cache.h
Simple merge

diff --cc sha1_file.c
Simple merge