triggerRegrab() is useful but hard to use

[lionleaf]

I spent some time at the hackathon trying to implement a GadgetSeed-like behaviour for caardvark. I want to be able to start grabbing the "new card button" and have the new card be spawned and immediately grabbed, like when you drag a gadget out of the menu.

Registering a callback on startGrab to spawn the new card is straight forward, but using the triggerRegrab function is not unless I'm missing something. I faced two main issues:

1. You can't call triggerRegrab() on an AvStandardGrabbable since the moveable component is private (I had to fork AvStandardMoveable).
2. It is not clear what reference to pass into triggerRegrab() for it to actually initiate a grab on the object you want. This one I never figured out before running out of time.

Maybe a wrapper function in AvStandardGrabbable is all that's required?