whitespace
code formatting: JShint & JSCS happiness (and me happy: standard coding patterns to prevent fuckups and regular, consistent code view for easier readability)
fixed nasty crash when userland drag event handler would return TRUE or some other truthy value that is not an HTMLElement or jQuery Element: the event handler's result should *always* be fed through drag.element(). In this case it was SlickGrid's standard Event.notify() method which returns TRUE when no userland handler is registered, thus returning a known, non-undefined value (which might otherwise come from anywhere) which DOES NOT signal the event handler to 'abort/terminate' (return FALSE would do *that*).

The main culprit turned out to be at line 361:
```
ia.results.push( result || subject );
```
-->
```
ia.results.push( drag.element( result ) || subject );
```
which now matches the behaviour of all other spots where the event result is picked up and used.

- Also completed the interaction object on creation for improved readability / searchability of the code.