TODO:
====
- run python code guideline checker
- more code documentation
- move all cache handling to decorators in ifupdownaddons package
- input validation (present in some cases not all)
- support the vlan0004 style vlans
- ifquery coverage. currently it is at 80%.
- vxlan module
- fix and release ifaddon utility to manage module priorities
- Deep compare in query for address module (does not compare address attributes like scope)
- Maybe a pure netlink backend 
- improve caching
