Add a method to dataset/query to append a group of OR conditions to an existing where clause
Updated original method based on feedback to improve efficiency, added the inverse method (andGroupedOr) also
Merge pull request #82 from jkc/master

Add a method to dataset/query to append a group of OR conditions to an e...
v0.2.9

Updated model to store transformed values in the changed hash
Update docs for pr #82