Bug 913734 - Remove custom privilege setup for cut/copy/paste. r=mrbkap
Bug 913734 - Stop storing security policies on XPCWrappedNativeProtos. r=mrbkap

This is just a cache, so we can safely remove it without impacting correctness.
The rest of this mechanism goes away in subsequent patches.
Bug 913734 - Stop consulting domain policies in CAPS. r=mrbkap

The whole LookupPolicy juggernaut is basically a mechanism for setting custom
per-(protocol, origin, property, action) access control in the preferences
service.

There are two sets of preferences currently in all.js. One of them is set up
for mailnews, for the mailbox:, imap:, and news: protocols. According to jst,
this was designed as a whack-a-mole security mechanism for javascript running
in HTML email. IIUC, we no longer allow JS to run at all in mailnews, so this
is obsolete.

The other mechanism appears to be our old-fashioned implementation of the
same-origin policy, which has been obsoleted by the new compartment
architecture.

In addition, most of this stuff was obsoleted by the new dom bindings, since
these DOM classes no longer go through XPCWrappedNativeJSOps, and thus no
longer trigger these security checks at all.

We stop using the infrastructure in this patch, and rip it out in the next one.
Bug 913734 - Remove now-unused policy machinery. r=mrbkap
Bug 913734 - Remove EnabledID() machinery. r=mrbkap
Bug 913734 - Remove namespace mozilla::hotness. r=mrbkap