People are often trying to use ARel nodes inside ActiveRecord, and when they do so, lots of things can break, because ActiveRecord relies on Array#uniq and sometimes hash key equality to handle values that end up in wheres, havings, etc. By implementing equality for all the nodes, we should hopefully be able to prevent any nodes (even nodes containing other nodes) from failing an equality check they should otherwise pass, and alleviate many of these errors. Fixes #130
It is untested. There is no `@frame` variable. Presumably it is supposed to be `@framing`, but changing that shows that some of the tests *are* setting frame twice. I don't see why this level of strictness is necessary. If someone disagrees, they should add a test for this behaviour and make the other tests pass.