New files:
    src/lib/dhcp/packet_queue_mgr.h
    src/lib/dhcp/packet_queue_mgr4.cc
    src/lib/dhcp/packet_queue_mgr4.h
    src/lib/dhcp/packet_queue_mgr6.cc
    src/lib/dhcp/packet_queue_mgr6.h
    src/lib/dhcp/tests/packet_queue_mgr4_unittest.cc
    src/lib/dhcp/tests/packet_queue_mgr6_unittest.cc
    src/lib/dhcp/tests/packet_queue_testutils.h

src/bin/dhcp4/ctrl_dhcp4_srv.cc
    Cleaned up packet queue config block

src/bin/dhcp4/dhcp4_lexer.ll
src/bin/dhcp4/dhcp4_parser.yy
src/bin/dhcp4/tests/config_parser_unittest.cc
    added queue-type

src/bin/dhcp4/dhcp4_messages.mes
    added DHCP4_CONFIG_PACKET_QUEUE message

src/lib/dhcp/Makefile.am
    packet_queue_mgr.h
    packet_queue_mgr4.cc packet_queue_mgr4.h
    packet_queue_mgr6.cc packet_queue_mgr6.h

src/lib/dhcp/iface_mgr.*
    Replaced packet queue members with PQM members
    Added PQM instantion to IfaceMgr ctor

src/lib/dhcp/packet_queue.h
    added getInfo,getInfoStr

src/lib/dhcp/tests/Makefile.am
    packet_queue_mgr4_unittest.cc
    packet_queue_mgr6_unittest.cc

src/lib/dhcpsrv/parsers/queue_control_parser.cc
    added queue-type