Add the raw option to all Erlang FFI calls

[varnerac]

The raw option, which bypasses the Erlang file server, is used in some write operations Erlang FFI calls but not others, like read and read_file_info.

Would you accept a PR to make all file:* calls raw to avoid the Erlang file server?

[bcpeinhardt]

@varnerac yes I would! I think I looked into this before and for some reason the file module doesn't take :raw as an option on some of it's functions. Anywhere you see I can pass :raw and don't where it would be respected, I'd happily accept a PR.