Support tabDragStart/tabDragStop events.

[lincolnthree]

Addresses #347 and a few prior, now-closed requests.

[ihadeed]

We can know exactly when the dragging stopped if we listen to the container events & push it up to the parent.

This approach is still good -- we can merge it and improve later, unless if you would like to implement the idea above.

[lincolnthree]

I agree with "We can know exactly when the dragging stopped if we listen to the container events & push it up to the parent."

Actually I think it is necessary as the current approach using timeouts actually kills performance pretty horribly since it's constantly checking and cancelling the timeout. I took this PR originally from one you got a while ago, I'll update with the changes, but... I'm not sure what the best way to push events from container up is. It looks like I'll need to add a hook to the parent in the container, or vis-versa.

Regarding your specific code change requests/comments. I think these are all rendered non-applicable if we change this to use the actual container events, right?

[lincolnthree]

Nevermind. The events can just be bound in the template (duh..)

[lincolnthree]

Alright. Take a look at this. I think it's pretty clean now. Much more efficient for sure.

I'm not sure of the nuances of your gesture events, so hopefully I put things in the right place. Let me know what you think!

[lincolnthree]

hey @ihadeed. Just checking on your thoughts about this PR since update. I have a few more things I might send your way as well if I can get them cleaned up (including a "low graphics" mode") and the ability to pass through lifecycle to the active tab (willEnter, didEnter, willLeave, didLeave) etc.