Expose common.js through breach_module

Hi,

Currently the wiki states that we have to [make a copy of common.js](https://github.com/breach/breach_core/wiki/Creating-a-new-module#debugging-the-module) when creating a new module. Couldn't it be exposed through the breach_module package ?

```js
var breach = require('breach_module');
var common = breach.common;
```

I'm currently hacking away with

```js
var common = require('breach_module/lib/common');
```

but this doesn't feel quite right.