Analysis Node Edtors - tooltips on elements

Apparently you can do it via forms:

```
class ExampleSettingForm(ModelForm):
def __init__(self, *args, **kwargs):
super(ExampleSettingForm, self).__init__(*args, **kwargs)
self.fields['example_field'].widget.attrs['class'] = 'css_class'
class Meta:
model = Example
help_texts = {
'example_field': ('Here is some help'),
}
```

Motivated by question asking what DamageNode "allow null" means - allows for when damage calculation wasn't performed, as only on dbNSFP - ie "all potential non-synonymous single-nucleotide variants"

James says you can add css class ```hover-detail``` to tell if something has a tooltip