bcardarella/client_side_validations — pull request #223 by mat813 (2011-11-16 15:09:52+00:00)
Title: Add the ability to not validate a numeric field if it can be empty.

If one does a :

```
validates_numericality_of :foo, :allow_nil => true
```

The javascript validation won't let you submit the form if the field is empty.