UBUNTU: [debian] add an autopkgtest rebuild test

The plan here is for linux, gcc, binutils, and eglibc to all depends on
each other and to all have a rebuild test.  That way the entire set is
rebuild tested for any one in the set being uploaded.

BugLink: http://bugs.launchpad.net/bugs/1081500Signed-off-by: Andy Whitcroft <apw@canonical.com>

debian/tests/control

+Tests: rebuild
+Depends:
+Restrictions: build-needed

debian/tests/rebuild

+#!/bin/true