Add unitests for VMware vif, and fix code logical error.
Add unitests for VMware vif, and fix code logical error.

Fix code logical error that cause variable referenced before assignment.
Add unittests for vmwareapi vif.

Fix bug #1177635

Change-Id: I6656e8b77417061eca2a56d50820f5385c0ae987

n0ano/ganttclient