1.11.1 is the version in squeeze and lucid, and we know it works. We
also know that 1.10.1 in hardy and lenny doesn't, nor do 1.10 in etch
and 1.9.6 in dapper. We haven't tested any other version.

With older versions python.m4 is buggy, and results in the package being
built not working on python 2.6 (which uses dist-packages rather than
site-packages as a module directory).

Version comparison is done component-by-component, over a bash array.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>