Implement is_new() in Paris

[treffynnon]

In idiorm there is an is_new() method but it is not implemented in Paris yet.

[tag]

I like that it's been added to ORM, but we need to be very careful when adding methods to Model, as it's reasonable to expect some model may have a similarly named method.

As $someModel->orm is public, this is still accessible to the end user through the orm property.

[treffynnon]

You're right it is a dangerous line to walk down and I am sure there will be bug report at some point mentioning a method clash! Still most implementers will hopefully be following the changelog of the project. It is a real toss-up between convenience and protecting against BC breaks - it is tough to decide for sure.