Merge branch 'release/0.2.9' into develop
* Added argument to prevent duplicate joins
* Do not allow duplicate groupings and joins

* Explicitly set field list when wrapping query
* Added method to remove field
* Only check the field identifier
* Prevent duplicate fields from being added
* Commented out debugging log
* Return 0 otherwise results will be unexpected
0.2.10
Merge branch 'release/0.2.10'