Update README to mention pkg-config and current configure
Update README to mention pkg-config and current configure

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

ojkastl/lxc_Patches,ojkastl/lxc_Patches,ojkastl/lxc_Patches,ojkastl/lxc_Patches