Make all imports either use full package name starting with `pungi` or
use explicitly relative import. This will avoid issues when importing a
module that shadows another module on PYTHONPATH.
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
Instead of hardcoding /usr/bin/python in shebangs, use /usr/bin/env.
This allows Pungi to work with dependencies installed in virtualenv.
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
The default is /usr/share/pungi/multilib/, pass --multilibconf to
override this.
This also adds multilib.init() so that an import of multilib doesn't
immediately setup the classes.
(cherry picked from commit 234524296fd53871aed64690cf6a7d5849ca154a)
