Update ubuntu and ubuntu-debootstrap for CVE-2014-7206

Note that for ubuntu-debootstrap, this only includes a regeneration of 12.04 and 14.04 because 10.04 is not affected and 14.10/devel does not have the fix yet.
Merge pull request #256 from tianon/ubuntu

Update ubuntu and ubuntu-debootstrap for CVE-2014-7206