pass schema as an object

- overall cleanup
- use mongodb-extended-json
- add a test for schema object
- now you can do:
```javascript
datasets(1, {email:
"{{chance.email()}}"}).pipe(datasets.stringify()).pipe(process.stdout)
```
debugging
Merge branch 'dev' into create-readable-from-object

Conflicts:
	lib/generator.js
	lib/schema/document.js
trying to get sorted...
add an assert
fix object literal handling
be a nice neighbor
Merge pull request #31 from imlucas/create-readable-from-object

pass schema as an object