Expose compileSpec to node's main export.
Expose compileSpec to node's main export.

Allows the following:

```js
var glimmer = require('glimmer-engine');
glimmer.compileSpec('{{foo-bar}}');
```

chadhietala/glimmer,tildeio/glimmer,glimmerjs/glimmer-vm,glimmerjs/glimmer-vm,glimmerjs/glimmer-vm,chadhietala/glimmer,tildeio/glimmer,lbdm44/glimmer-vm,chadhietala/glimmer,lbdm44/glimmer-vm,tildeio/glimmer,chadhietala/glimmer,lbdm44/glimmer-vm