[fix bug 1059714] Add 'Save As' button for Snippets and JsonSnippets.

We force disabled=True for cloned snippets to avoid mistakes.
ATTACK OF THE HANGING INDENT :P

In cases like this I like to go with a 4-space indent for readability.

```python
request = self.factory.post('/', data={
    'name': 'test',
    'template': 'foo',
})
```