src/bin/admin/tests/dhcpdb_create_5.1.mysql - deleted

src/bin/admin/tests/mysql_tests.sh.in
    mysql_upgrade_schema_to_version()  - new function which
    upgrades an existing schema to a target version

    mysql_lease_stat_upgrade_test() - modified to start with
    1.0 schema and then use new function to upgrade to 4.0

src/lib/dhcpsrv/tests/mysql_lease_mgr_unittest.cc
    mysql_lease_mgr_unittest.cc
        Added condition compilation around INVALID_HOST scenario
        that causes db connectivity tests to fail