src/lib/dhcpsrv/cfg_subnets4.cc
    CfgSubnets4::updateStatistics() -  replaced recountAddressStats4()
    with recountLeaseStats4()

src/lib/dhcpsrv/cfg_subnets6.cc
    CfgSubnets6::updateStatistics() - replaced recountAddressStats6()
    with recountLeaseStats6()

src/lib/dhcpsrv/lease_mgr.cc
    renamed LeaseMgr::recountAddressStats4() to recountLeaseStats4()
    renamed LeaseMgr::recountAddressStats6() to recountLeaseStats6()
    renamed LeaseMgr::startAddressStats4() to startLeaseStats4()
    renamed LeaseMgr::startAddressStats6() to startLeaseStats6()

src/lib/dhcpsrv/lease_mgr.h
    replaced AddressStatsRow4 and AddressStatsRow6 with single class,
    LeaseStatsRow

    replaced AddressStatsQuery4 and AddressStatsQuery6 with single class,
    AddressStatsQuery

src/lib/dhcpsrv/memfile_lease_mgr.h
src/lib/dhcpsrv/memfile_lease_mgr.cc
    Replaced this class heirarchy:
    AddressStatsQuery4 <-- MemfileAddressStatsQuery4
    AddressStatsQuery6 <-- MemfileAddressStatsQuery6

    With this one:
    LeaseStatsQuery
        |
        +--- MemfileLeaseStatsQuery
               |
               +--- MemfileLeaseStatsQuery4
               |
               +--- MemfileLeaseStatsQuery6

    Replaced startAddressStatsQuery4() with startLeaseStatsQuery4()
    Replaced startAddressStatsQuery6() with startLeaseStatsQuery6()

src/lib/dhcpsrv/tests/generic_lease_mgr_unittest.h
src/lib/dhcpsrv/tests/generic_lease_mgr_unittest.cc
    Renamed:
     checkAddressStats() to checkLeaseStats()
     testAddressLeaseStats4() to testRecountLeaseStats4()
     testAddressLeaseStats6() to testRecountLeaseStats6()

src/lib/dhcpsrv/tests/memfile_lease_mgr_unittest.cc
    Renamed tests to recountLeaseStats4 and recountLeaseStats6