Issue #2244513 by kim.pepper, phenaproxima, 20th, andrei.dincu, beejeebus, Berdir, jibran, alexpott, andypost, larowlan, Chadwick Wood, Wim Leers, acbramley, YesCT, sun, tim.plunkett, chx: Move the unmanaged file APIs to the file_system service (file.inc)