Global EXIF switches

[dswtan]

Please let me know if I'm missing something, but I would like:

- An account switch for whether EXIF is shown or not in all galleries under the account by default, including new galleries created later.
- An "and all subgalleries" switch for whether EXIF is shown or not in all subgalleries as well as the current gallery.

Similar to the "Advanced Passkey Settings".

Thanks!