(trunk, libt) #4160 - the slow slog to catch trunk up to mike.dld's 4160 diff continues. This step applies 4160-03b-file.patch, which replaces native file operations with the tr_sys_file_*() portability wrappers added in r14321.

git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14327 f4695dd4-2c0a-0410-b89c-da849a56a58e