Merge branch 'lt/config-fsync'

* 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 config.c
Simple merge

diff --cc environment.c
Simple merge

diff --cc sha1_file.c
Simple merge