Code review comment for lp:~bregma/libgrip/lp-744911

Thanks for the docs (and the link) Stephen!

So I have one comment, and you're free to go either route. But first, here's a list of the components that seem to be missing documentation:
 * struct GripGestureManagerClass
 * union GripGestureEvent
 * struct GripEventGestureAny
 * grip_gesture_event_new ()
 * grip_gesture_event_free ()
 * grip_gesture_event_copy ()

We should do one of the following:

 1) add docs (even a short one-sentence description) for the 6 listed above, or
 2) be prepared to update the docs when asked by community members.

I'd prefer option #1, but if it's a matter of being unclear of the exact usage, and there being too much overhead in tracking down the folks that know, we can do #2.

However, if we go that route, it means that we need to be *very* conscientious: as soon as we answer a question in-channel (or mail list) or find an answer out from someone who knows, we need to file a ticket to update the docs, and add that information immediately.

I will set my review to "approve" -- however, don't merge yet. Let's get a review from David Planella.