Make curly into a gem that installs a binary executable

The `curly` command! Feel free to toss this in a branch if you'd rather keep it simple. You can do this to install now:

```
$ git clone THISREPO
$ gem build curly.gemspec
$ gem install curly-0.0.1.gem
```

You could also push it to rubygems too if so inclined, it should be just one command:

```
$ gem push curly-0.0.1.gem
$ gem install curly
```