Debian (and therefore Ubuntu) have taken to hiding some libraries
awkwardly, leading to Python 2.6 failing to build.

Python 2.7 builds ok, because it has been taught to deal with this.
This patch retro-fits the 2.7 code into 2.6, and allows 2.6 to build on
Ubuntu 11.04.

Ok'd by wiz@

(dsainty)