Add .griveignore

[rakshazi]

Hello @vitalif !
Please, add ability to ignore files and dirs via separate file, eg: .griveignore.
Syntax can be as .gitignore files, because it's most used fromat. Specifications: https://git-scm.com/docs/gitignore

Best regards,
Nikita Chernyi.

pS: I don't know C/C++, thats why I can't do it and PR myself, sorry :(

[rakshazi]

@vitalif hello!
Can you implement this feature, please?

[Slaedr]

Indeed, that would be very useful. I know some C++, but I'm totally new to the tools used by @vitalif, like yajl. Perhaps I'll try something over the winter if time permits.

[vitalif]

In fact it's rather simple because .ignore is easily translated into a regexp. Ok, I'll implement it if everyone wants it so hard :)