Remove ESXDriver from Juno.

1. Removes the VMwareESXDriver code in nova/virt/vmwareapi/driver.py
by either deleting the redundant methods or moving them to
VMwareVCDriver.
2. Changes the test cases to use VMwareVCDriver and also removes
duplicate test cases which were previously being testing both
VMwareESXDriver and VMwareVCDriver to just the latter.

DocImpact
Closes-Bug: #1346637
Change-Id: I718fc0ee67dbd625af00c20fa4e34b8a35015437
Catch NeutronClientException when showing a network

When a network id can't be found, neutronclient raise
NetworkNotFoundClient exception, but this exception is not
handled by nova. This will cause a 500 error.
This patch fixes this bug.

Closes-Bug: #1286969
Change-Id: Ia96c9668c74374476d4dccdbdb281e99d91b0088
Merge "Remove ESXDriver from Juno."
Merge "Catch NeutronClientException when showing a network"