utils.external_packages: Introduce minimum_version
Some python modules, such as setup tools, might have
a minimum version under which the needed functionality for
autotest is OK. In case of setup tools, any version equal
or higher than 0.6 is OK, but in case the module is completely
missing, we'll install 0.6c11, which is the latest upstream.
So, make possible to specify 'minimum versions' for packages,
if we have that one, make the is_needed check with that version.
Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
git-svn-id: svn://test.kernel.org/autotest/trunk@5445 592f7852-d20e-0410-864c-8624ca9c26a4