Add role and user factory functions.
Change instances where None is returned by SWIG to raise exceptions instead
Change inheritance for MLSDisabled and NoCommon exceptions.
Comment fix in policyrep __init__.
Documentation fix in PermisiveQuery.
Whitespace fix in SELinuxPolicy
Add mls, version, and handle unknown policy properties.
Restructure seinfo

* Restructure queries to only have one output
* Fix portcon help info to be clearer about specifying ports
* Cover all functions with exception handling
Implement policy statistics functions.

Do counting in C where possible.
PEP8 fixes in seinfo
Switch SELinuxPolicy terules and rbacrules generators to use chain().
Fix copy-paste error in seinfo.
Whitespace fix in Common.