Import unmodified implementation done by @boring-stuff.
Full history for reference is available in rpc-confirmation-window
branch.
QubesOS/qubes-issues#910
This socket (and commands) are not exposed to untrusted input, so no
need to extensive sanitization. Also, there is no need to provide a
stable API here, as those methods are used internally only.
QubesOS/qubes-issues#853
This is rewritten version of core-admin-linux/qrexec/qrexec-policy.
It's placed outside of `qubes` module on purpose - to avoid imporing it,
which require a lot of time.
QubesOS/qubes-issues#865QubesOS/qubes-issues#910
