
Adding logger support. The default log file will be nsx_migration.log in the work directory. It can be changed using the --logfile option. In addition, add some minor fixes, and handle the case of 2 dhcp-enabled subnets which is not supported by the v3 plugin. Change-Id: Ie0f1aa2e8b4b23fbbf2036a2df6cc78634b027b3