file.js:
  - watch_directory() WIP
  - refactor watch() to become base class for watch_directory()
  - use extend_2() instead of extend() when applicable
  - content_to_set(): remove update code, let Pipelet handle transactions
  - watch(), use Build with methods function to use Super
  - watch(), add 'eot', 'ttf', 'woff' as non-utf8 encoded files