Merge with Michael and add update-po as a pre-req for binary

Merge with Michael and add update-po as a pre-req for binary
* po/makefile: Add update-po as a prerequisite of binary. Closes: #329910

Patches applied:

 * michael.vogt@ubuntu.com--2005/apt--mvo--0--patch-78
   * fix a incorrect example

 * michael.vogt@ubuntu.com--2005/apt--mvo--0--patch-79
   * revert patch from patch-59, causes all sorts of trouble

 * michael.vogt@ubuntu.com--2005/apt--mvo--0--patch-80
   * fix changelog

 * michael.vogt@ubuntu.com--2005/apt--mvo--0--patch-81
   * be extra carefull in cmdline/apt-get.cc:FindSrc() and check VF.File() for NULL