Fix error when updateImageAttributes dispatched
Fix error when updateImageAttributes dispatched

An uncaught error has been occurring when an image creator saves any
changes to image attributes:

```
Uncaught TypeError: Cannot read property 'silent' of undefined
```

It turns out that the HelpLinkStore is performing check for an option,
`option.silent`, to determine if an `emitChange()` call should be made.

Unfortunately, this "check" is done in a manner that generates the
above uncaught type error.

The fix was to use the `_.has(obj, "propName")` call. This could be
replaced with an expression like `obj && obj.hasOwnProperty("prop")`,
but here we opt for `underscore` since it is already available - we
could also move to `lodash`.

CCI-MOC/GUI-Frontend,CCI-MOC/GUI-Frontend,CCI-MOC/GUI-Frontend,CCI-MOC/GUI-Frontend,CCI-MOC/GUI-Frontend