Kill domAttributeWhitelist in favor or renderHtmlAttributes

domAttributeWhitelist wasn't actually being observed. Instead, we
already had the code in place to treat renderHtmlAttributes as a
boolean/whitelist/blacklist hybrid, it just wasn't used that way
yet.

This makes the interface nicer and fixes the bug where all attributes
(including data-parsoid and even things like onmouseover) were
rendered by CE.

Change-Id: I02e266c7c7dc197ed845164b7a705d786846a33b
Merge "Kill domAttributeWhitelist in favor or renderHtmlAttributes"