gui: Several python 3 related fixes from fedora-selinux/selinux
    
    - gui/polgengui.py: Fix sepolicy.generate import in polgengui.py
    - gui/polgengui.py: Convert polgen.glade to Builder format polgen.ui
    - python/sepolicy: Use list instead of map
    - python/sepolicy: Do not use types.BooleanType