naga v1.0

Naga is a terminal implementation of snake game. URL: http://github.com/anayjoshi/naga.
This is a first time addition of this project in homebrew. The project has existed for quite some time, the github repository was refurnished today.
There's a special `scons` helper, which works around the possibility of having other, incompatible sconses installed. `scons` is a function that calls the Homebrew-provided scons with the requested arguments; it's the same as doing:

```rb
system Formula["scons"].bin/"scons", "install" , "install_path=#{bin}"
```