Update context on transact, in addition to select

* Cleanup documentation of ve.dm.Surface, LIES LIES LIES!
* Combine select with documentUpdate and debounce them so we don't
  double-update when there's a transaction that causes a selection
  change.

Change-Id: Iaff6d440cd39872a4a723ae65a34c52109667f41
Add class to internal item nodes

It was totally missing dude

Change-Id: Icfe5f65178c96cc3e1b8f6d9385fa251235d17da
Merge "Update context on transact, in addition to select"
Merge "Add class to internal item nodes"