Installer build fails right out the gate with method error

```
make

node_modules/.bin/iced -I browserify -c -o `dirname lib/base.js` src/base.iced
TypeError: Object # has no method 'exists'
at writeJs (/home/user/projects/privacy/node-installer /node_modules/iced-coffee-script/lib/coffee-script/command.js:477:15)
at compileScript (/home/user/projects/privacy/node-installer/node_modules/iced-coffee-script/lib/coffee-script/command.js:229:18)
at compilePath (/home/user/projects/privacy/node-installer/node_modules/iced-coffee-script/lib/coffee-script/command.js:164:14)
at Object.exports.run (/home/user/projects/privacy/node-installer/node_modules/iced-coffee-script/lib/coffee-script/command.js:99:21)
at Object. (/home/user/projects/privacy/node-installer/node_modules/iced-coffee-script/bin/coffee:7:41)
at Module._compile (module.js:446:26)
at Object.Module._extensions..js (module.js:464:10)
at Module.load (module.js:353:32)
at Function.Module._load (module.js:311:12)
at Array.Module.runMain [as 0] (module.js:484:10)
at EventEmitter.startup.processNextTick.process._tickCallback (node.js:190:39)
```

Node version 0.6.19
Linux amd64 3.8.0-35-generic Ubuntu 12.10

Start by running make and reviewing the iced command compiling src/base.iced, especially the reported writeJs failure in node_modules/iced-coffee-script/lib/coffee-script/command.js. Compare the build behavior with the reported Node 0.6.19 environment; done means the installer build completes without the Object.exists method error.

Written by the indexing model from the issue text.