add missing license headers
raise error if parsing unknown field
ugly hack to fix darn lines (once again)

The new converter uses getattr to fetch data from a model.
but the old abstract models doesn't set a value if it's null, which
causes a lot of mayhem. This is a quick fix until we migrate
lines onto the new model architecture
fix damned sip lines tests
Merge pull request #15 from xivo-pbx/fix_confd_tests

Fix confd tests