L10n:Review Firefox

This is just a sketch of things to watch out for when reviewing locales for Firefox:

• all top-level directories need to exist, those are as of now
  • netwerk
  • dom
  • toolkit
  • security/manager
  • browser
  • other-licenses/branding/firefox
  • extensions/reporter
• check bookmarks.html according to L10n:Firefox Extras
• search engines, too
• check MOZ_LANGPACK_EID application/defines.inc, the en-US one is {f68df430-4534-4473-8ca4-d5de32268a8d}