Output hosts records to file

[nfourtythree]

This could be a file in the ~/.nitro directory.

The reason for this is that if you using apps such as switch hosts or gas mask you can use the file as a remote and have it combine with other custom host records.

This goes hand in hand with #110

[lukeholder]

A note for others who use gasmask, I had to turn of 'override external modifications' in gasmask preferences to let nitro edit the main host file. Gasmask was monitoring it and reverting any changes made by 3rd parties.

[nfourtythree]

@jasonmccallister would be amazing to get this now that #110 is possible!

[jasonmccallister]

Maybe I am an edge case, which would not be the first time :), but I have never used tools like this for hosts files. Is this an edge case? I'm curious how we would work this into a config so we know when we should write to the external file.

Otherwise would this require everyone to use a tool like this?