RFC - use lodash's main instead of ours

## Before

```
./static/target/javascripts/bootstraps/app.js
Size:		214.38 Kb
Gzip Size:	65.57 Kb

./static/target/javascripts/core.js
Size:		114.53 Kb
Gzip Size:	37.76 Kb
```

## After

```
./static/target/javascripts/bootstraps/app.js
Size:		213.09 Kb
Gzip Size:	65.06 Kb

./static/target/javascripts/core.js
Size:		142.14 Kb
Gzip Size:	44.54 Kb
```

### Pros

 * Simplify usage of `_` (don't need to check if function's already in there)
 * Safeguard against issue of using lodash's `_` and our `_` - they aren't compatiable

### Cons

 * Increase size of `core.js`