Changelog:
- Fix CiscoRange() should automatically prune duplicates added to the list
- Fix ciscoconfparse.ccp_util.CiscoRange() should support emtpy ranges
- Fix ciscoconfparse.models_cisco needs an explicit MAX_VLAN constant
- Fix IOSCfgLine().re_match_typed() doesn't have an 'untyped_default' boolean
- Fix trunk_vlans_allowed returns only two lines
Approved by: (one of the mentors)