Add status and request functions for external Volumes access

[SinghManmohan]

@codebytere : Can we have node-mac-permissions module control OS dialog regarding removable volume too?
We would like to handle "Do not Allow" case if user selects that option.

[codebytere]

Good question! i'll look into whether it's possible :)

[SinghManmohan]

@codebytere : Any luck getting onto this yet?