Expose virtual PID from child namespace in /proc/PID/status.

The virtual PID is used by Ubuntu Touch application manager code ( which
runs in the Android namespace ), to communicate with code that runs inside the
Ubuntu container.

This patch is not from upstream.  It was proposed on the lxc-users
mailing list:

http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg01840.html

Change-Id: If63652002c227827fb524e03a1d0210fc2b7d4b1
Original-Author: Greg Kurz <gkurz@fr.ibm.com>
Signed-off-by: Greg Kurz <gkurz@fr.ibm.com>
Signed-off-by: Tony Espy <espy@canonical.com>
Signed-off-by: Ricardo Salveti de Araujo <ricardo.salveti@canonical.com>
Add permission checking for binder IPC.

Change-Id: Ia224e29427d39a6eeb0800a65ad2a8df2e91bebc

Conflicts:
	drivers/staging/android/binder.c
Fix security_binder_transfer_binder hook.

Drop the owning task argument to security_binder_transfer_binder
since ref->node->proc can be NULL (dead owner?).
Revise the SELinux checking to apply a single transfer check between
the source and destination tasks.  Owning task is no longer relevant.
Drop the receive permission definition as it is no longer used.

This makes the transfer permission similar to the call permission; it is only
useful if you want to allow a binder IPC between two tasks (call permission)
but deny passing of binder references between them (transfer permission).

Change-Id: I6ec460ede8e07dadc9f52b61534b2b0021617302
Build script: update toolchain path