Track the object element during init and remove it if the tech is dispos...

...ed before onReady. For #1339.

If dispose() was called before the SWF triggered onReady(), the placeholder div would be cleaned up but the actual object element would be left behind to mess things up in the future. Keep track of the object element during initialization and make sure it is removed if flash is unloaded early.
What if we just set this.el_ = obj here? Then component would remove that instead of the placeholder.

I think the main reason for not doing that before was that we were using swfobj which uses an object or embed depending on the platform, but now we built a custom object that works across platforms. I'm trying to remember if there were any other reasons. Either way if it works on IE8 we should be good, and that should simplify this.