fix looping with Gmail provider and auto mark-read. cleanup.

* only mark initially unread conversations read
* disable re-render on loader update for now. will re-enable
  later for specific cases like new message or updated draft,
  or when UI changes no longer trigger provider notifications

* properly invalidate cursor on loader reset
* pick a better loader ID for attachment list query
* disable scroll tracking before geometry is known
* ignore JS callbacks after views are destroyed

Change-Id: I6cec7186dab301d57995a73df0c3506549a7932d
3 files changed