Fsyncing the file has a small performance penalty and seems unnecessary. The
file will be fsynced anyway, when the changes are commited to the database.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3749
These are no longer required with Go 1.7. Change made by removing the
functions, doing a global s/osutil.Remove/os.Remove/.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3514