Merge branch 'negation_support'

* negation_support:
  fix negation handling for complex arguments
  Use a more generic way for parsing negated options, not only for destination and source
  Added a test case for /older/ alternative negation syntax
  Generic generating command line options for negated rules
  spec test fixtures should represent real use cases
  Fix parsing of rules and generating the command line to set the rule
  Fix parsing negated values
  Added fixtures to test parsing negated addresses
  Add test to see if type takes negative values
  Use host_to_mask so we can negate a mask. Also added documentation.
  Added host_to_mask method and added tests for it
Merge branch 'purge'

* purge:
  add support for removing unmanaged firewall rules
Merge branch 'nat_input'

* nat_input:
  allow input chain in nat table