If you're reading this commit history, please avert your eyes. 3
commits to fix this admittedly simple problem is more than my pride can handle.
The `gun.Back()` function was only searching for `opt`, not
`opt.file`. It would stop at the first mention of `opt` even if it
didn't have settings for `file`. Now it won't.
The FileJS module can be passed options in two ways, and this commit
ensures they're treated in the right way.
Previously, options passed as .put or .get parameters would be favored
over those used on the chain, even if `file` wasn't specified. Now, the
module will only use the method options if `file` is mentioned, falling
back to the chain options.
This was a mistake on my part with the first PR (#268), I failed to notice notice that edge case.
If the most recent gun options disable the file module, then it
won't try to read/write from the json. Previously it would. Also, now
you can override the behavior by passing `{ file: false }` as the
options in `gun.put`.
