Fixes indentation on mysql driver file
Adds a Tools file with some special objects to use in .find() conditions
Exports Tools methods to create the previously created special objects
Changes sql SELECT to support special objects in condition values (fixes #19)

Example:

```js
Person.find({ age: orm.between(20, 30) }, cb);
```

Other special objects:

- orm.eq(val): equal to val
- orm.ne(val): not equal to val
- orm.gt(val): greater than val
- orm.gte(val): greater or equal to val
- orm.lt(val): lesser than val
- orm.lte(val): lesser or equal to val