Using db.XX.count in pager to count results 

Closes #103

Before: 
```
db.book.find().sort({ "title.name": 1 });
db.book.find().skip(0).limit(25).sort({ "title.name": 1 });
```

After:
```
db.book.count();
db.book.find().skip(0).limit(25).sort({ "title.name": 1 });