(Or technically 125, but I don't think any strings we need were
removed)
This fixes the Edit and Window menu (except for some macOS Window
strings that seem to come from the system) in non-English locales.
- Properly handle regular vs. Mozilla locale files
- Avoid whitespaces changes as much as possible
- Keep copyright block at top of all Mozilla files
- Bug fixes
All declared Fluent files need to exist for a locale to be used (in a
window?). Since Mozilla code tries to load Fluent files, we need to copy
non-English Mozilla .ftl files to their default effective path (just in
the app omni.ja instead of the toolkit omni.ja).
Fixes#3094