minijail0: add chroot support.

Support a -C commandline option to chroot(), and a -b commandline option to
bind-mount paths into the chroot from outside.

BUG=chromium-os:21165
TESTED_ON=kaen
TEST=None yet

Change-Id: Ia6a7a4498968a4bc6a12f8274fdb8c4be9d23ca4
Signed-off-by: Elly Jones <ellyjones@chromium.org>
Reviewed-on: http://gerrit.chromium.org/gerrit/8661
Reviewed-by: Kees Cook <keescook@chromium.org>
4 files changed