1. Since the nsxv plugin was defined globally in one of the utilities files,
it was actually initialized for all the nsxv utilities, which has some side
affects (like deploying backup edges during unrelated admin utilities in case
some of the pools are not full), and also takes a long time.
Now the plugin is initialized only when needed.
2. When the plugin is initialized during an admin-util call,
we mustn't exit while spawn jobs for creating edges are still running,
or else - those edges will be in PENDING-CREATE state for ever.
Initializing the plugin using "with" and adding an exit method which waits for
the jobs to finish solved this issue.
Change-Id: Ia1fa557a8da149f79a46b3ca49b122f991b2ca9b
a7d43ec275